Archive of Our Own

As you may already know, this world is riddled with demons. Human-like creatures that come out in the dead of night and feast upon humans' flesh to survive. They possess strength, regeneration, and supernatural abilities known as Blood Demon Arts. 

To combat the demons, a secret organization fights to protect humanity. Those who serve this organization combat the demons using special elemental breathing techniques known as "Breathing Styles" while wielding swords made of a special alloy called Nichirin or utilizing a poison made from a unique flower called wisteria. 

This organization is the Demon Slayer Corps. 

However, an alternative world exists. 

In this world, the characters of Demon Slayer attend a private school for elementary, middle, and high school students, where countless shenanigans ensue, and they live everyday lives. 

This school is Kimetsu Academy. 

Some of the characters attend this school as students, while others work there as teachers. However, this story will focus on one person in particular.

Her name is Shinobu Koccho. 

She is a young, petite woman with fair white skin, hazy purple eyes, rosy pink lips, and black hair that fades to violet. Her hair is styled in a bun with a butterfly ornament. 

In the Demon Slayer world, she doesn't possess the strength to kill a demon on her own, but she makes up for it with her knowledge of poisons and medical expertise, her agility, and her ingenuity. Those abilities make her one of the twelve Hashira, a rank given to demon slayers of the highest rank. 

However, in the world of Kimestsu Academy, things are vastly different. Shinobu is a third-year student, president of both the Pharmacology and Fencing clubs, and has won Miss Kimetsu every year. She excels at both P.E. and academics and is well-liked by her juniors. 

To those who know her well, she displays a cheerful disposition, is always easygoing, and seems to be smiling no matter the situation. However, that is nothing more than a facade. Underneath it, there is a side to her that makes everyone fear her, even the teachers.

Firstly, like her original self, Shinobu loves teasing others to the point of being sadistic, most notably towards the P.E. teacher and guidance counselor, Giyu Tomioka. In addition, strange rumors have circled the school about how she loves to make dangerous kinds of drugs in the pharmacology club and would look around to find an unsuspecting victim to experiment on. It's because of this that a few people gave her the nickname "Poison Princess." 

And in this story, one of these drugs will cause a lot of trouble in both big and small ways. 

Class was about to start. 

Tanjiro was feeling bright and cheerful as he made his way to his desk. 

"All right! Time to go and meet Nezuko!" he said to himself. 

But as he sat down, Zenitsu approached him, jubilant as well.
 
"Hey, Tanjiro. You going to go eat with Nezuko during lunch period?" he asked cheerily. "Mind if I tag along?" 

"Of course you can, Zenitsu. The more the merrier, as they say," replied Tanjiro. "Besides, I made a lot of bread today, and I wouldn't want it all to go to waste. Inosuke might want some, too, so I was going to find him, too."

Zenitsu's face fell. "Must you invite him?" he asked, sighing. "That idiot's going to ruin my special time with Nezuko. He's nothing but trouble." 

"Come on, Zenitsu. He's not that bad," said Tanjiro. "Besides, I'd feel bad if I left him out. It wouldn't be right." 

Then he looked towards an empty desk, which happened to be Inosuke's.

"Although, now that I think about it, I haven't seen him since the last class," he said, frowning. "I wonder where he is? The bell's going to ring in a few minutes." 

"I wouldn't worry about that delinquent," scoffed Zenitsu. "Knowing him, he's likely planning his next prank." 

Just then, the door swung open, and Inosuke came strolling in. He was shifty-eyed as he glanced around back and forth before sliding into the classroom, sniggering mischievously to himself as he came over to his seat. 

"Oh, there you are, Inosuke," said Tanjiro. "You seem to be in a good mood. May I ask why?"

Inosuke then dug into his schoolbag and pulled out a small, corked test tube containing pink fluid. "Because I've come up with the ultimate prank," he said. "When the teacher comes in, I'm going to put this in their drink and see what happens." 

"I should've known you'd be up to no good," Zenitsu sighed. "Just what I'd expect from a-." 

Then, both his and Tanjiro's faces paled upon seeing the test tube, knowing exactly where it came from. 

"Um, Inosuke? You wouldn't have happened to have gotten that tube from the Pharmacology Clubroom, would you?" Tanjiro asked nervously. 

"Yeah? So what if I did?" asked Inosuke.

"Are you insane?!" Zenitsu screeched in alarm. "Don't you realize that you've taken not only club property but you're also carrying a potential biohazard?! Especially since it's likely one of Shinobu's crazy drugs!"

"So what?! That means it's bound to do something cool!" Inosuke grinned. 

He then eyed the front desk at the front of the classroom and saw a cup of water on top of its surface. Grinning mischievously, he made his way toward it, intent on seeing his plan through. 

Tanjiro and Zenitsu were about to stop him, but then, the classroom slammed open, followed by the shrill sound of a whistle blowing. Then, Giyu, the P.E. teacher and guidance counselor, stomped inside.

"Inosuke Hashibira!" he barked. "You're in big trouble, young man!" 

Feeling startled, Inosuke jumped, causing the tube to slip from his grasp and, much to Tanjiro and Zenitsu's horror, hit the floor. Upon impact, a massive explosion erupted with a loud boom, and pink smoke billowed everywhere. 

When Tanjiro next opened his eyes, he found himself lying on his back, dazed and surprised. "Ow, that hurt," he groaned. "That explosion really knocked me out." 

He sat up, feeling his head, while getting up and looking around, before his eyes fell upon three shadows amongst the smoke. As he did, he heard a familiar shrill voice exclaim. 

"W-What the hell is this?!" 

Tanjiro then rushed over to the two shadows, and sure enough, as he got closer, one of them was Zenitsu and the other two were Giyu and Inosuke. 

"Hey, you guys! I'm glad you're all OK!" Tanjiro said, thankfully. "Is everyone all right?!" 

But everyone was staring into the distance. Giyu and Zenitsu's faces were filled with horror and dread, while Inosuke's was filled with delight and excitement. Tanjiro looked in their direction and soon found out why. 

As the smoke cleared, he found that, while they were still inside the classroom, there had been a startling change. The desks were now as tall as towers, the floor was vast and expansive, and everything else around the room was thrice as big. 

"W-What the heck?!" exclaimed Tanjiro. "Why did everything get so big?!"

"Everything didn't get bigger," said Giyu. "It's safe to assume that we shrank due to the concoction." 

"Whoa, this is so cool!" Inosuke cried out excitedly. "Everything looks so ginormous now! Bet I can prank the teacher no problem like this!" 

Zenitsu wailed, his face pale as he wept with horror. "This has to be a dream! It has to be!" he shrieked. "That explosion must have put me to sleep, and now I'm having a nightmare!" 

"Calm down, Zenitsu!" urged Tanjiro. "This isn't the time to panic!" 

"Don't you tell me not to panic because it's the perfect time to panic!"  Zenitsu snapped. "How can I when we're as small as ants that could be easily crushed by one stomp of someone's shoe?!" He then jabbed a finger at Inosuke. "And all because this idiot decided to take something from Shinobu's lab because he thought it would be funny!" 

"Hey! Who are you calling an idiot?!" Inosuke barked. "You looking for a fight?! I'll kick your ass!" 

Giyu then punched Zenitsu right on the cheek, knocking him flat on the floor. "Enough with your screaming!" he shouted. "This isn't the time to be acting like children!" 

Zenitsu, while having a spectacular red imprint on his cheek, could only groan as his body twitched. "Nope. I'm not dreaming," he mumbled while spitting some blood. "Otherwise, I wouldn't be feeling this pain." 

Giyu then turned to Tanjiro and Inosuke. "We need to get to the chem lab. It's her drug that caused this to happen, so it's likely there's some form of an antidote that turns us back to normal."

"That is a good idea, Mr. Tomioka, but there's just one problem," said Tanjiro. "How are we supposed to get there with us being so small? It's so far away." 

"The only way available to us," said Giyu. "We'll get there on foot."

Tanjiro, Inosuke, and Zenitsu all looked at Giyu in incredulous shock. "WHAT?!" they all exclaimed. 

"Are you crazy?! If we did that, someone's bound to step on us!" shrieked Zenitsu. "Plus, do you have any idea how far that room is?!" 

"We don't have a choice," said Giyu. "As long as we stay along the wall, we should be able to avoid anyone who comes by. So if you got time to complain, then we got time to run." 

"You must be out of your damn mind if you think I'm running that far!" Zenitsu snapped. "I'd rather be stepped on!"

Giyu gave Zenitsu a look. Then, he pulled out a black bottle from his pocket. As soon as Zenitsu saw it, his face went pale, recognizing it. 

"W-Wait! That's not what I think it is!" he cried. 

"That's right. It's black hair dye," said Giyu. "I happened to have this with me in case I ran into you, Zenitsu. I've been very lenient with your hair thus far, but now I think it's time for you to dye your hair as per school rules." 

"W-What?! You can't be serious!" Zenitsu snapped. "I told you I'm not dying my hair!" 

"Then you'd better get running, or else I'll dye it on the spot," warned Giyu. "And I'm giving you a thirty-second head start." 

Zenitsu immediately took off running as fast as his legs could carry him, and Giyu soon followed suit, sprinting after him. 

Inosuke also followed suit. "Hey! I didn't know we were racing!" he roared. "Don't think you'll beat me because I'll beat all of you first!" 

Tanjiro watched his three friends before deciding to give chase as well. "Well, at least we've got some kind of plan," he sighed. "Hopefully, we'll be back to normal soon before something goes wrong." 

About an hour later…

The group soon arrived at the chem lab, which, luckily for them, was empty.

"Looks like we were able to get inside with no issue," said Tanjiro. "And it doesn't look like anyone's here." 

"That's perfect," said Giyu. "At least we won't have to worry about anyone barging in on us while we look for the antitote. Now, we're going to split into two teams and search the area. I'll go one way, and the rest of you will look in another way." 

"Hold on a second," interjected Zenitsu. "How are we supposed to find anything, given that we're so small? And what are we even supposed to be looking for?"

"Just hurry up and start looking," Giyu spoke curtly. "We have to find something to turn us back to normal before we're spotted." 

Tanjiro could see that Giyu was tense. "Is something wrong, Mr. Tomioka?" he asked. "You look worried."

Before Giyu could answer, they suddenly heard a strange, repetitive booming sound. It came from outside the classroom, starting as a faint rumble that grew louder, while the ground began to tremble. It didn't take the group to realize that these were the sounds of footsteps.

Then the door swung open, and two familiar faces came in. One of them was Shinobu Kocho, president of the Pharmacology and Fencing Clubs, and the other was Kanao Tsuyuri, a member of the Flower Arrangement Club, as well as Shinobu's adoptive sister. 

"Oh, crap! It's Shinobu and Kanao!!" Tanjiro exclaimed. "What are they doing here?!"

"I don't know, but we need to run!" Giyu spoke urgently. "If they see us, we're finished!" 

But as they started to run, they noticed Inosuke and Zenitsu remained rooted to where they stood. Insosuke wore a cocky grin while cracking his knuckles, while Zenitsu was pink with lust, drooling like a fool. 

"What are you two doing?!" Tanjiro yelled. "Didn't you hear Mr. Tomioka?!"

"Sorry, Kanjiro, but there ain't no way I'm running!" Inosuke spoke with oblivious bravery. "This is the opportunity for revenge! That tiny chick's always beaten me back in P.E., but now the tables have turned! It's time to see how she likes it when she gets beaten by someone smaller than her!"

"Those girls are giants now, which means there's not only more to oogle, but being small like this means you check out their skirts from below!" Zenitsu spoke with enthusiasm. "Plus, being smothered by a woman is every guy's dream! You'd be an idiot not to pass up on this opportunity!" 

"I'm seriously starting to reconsider my friends here!" Tanjiro cried miserably.

Then, Shinobu's eyes fell in their direction, and her expression immediately darkened as she ominously smirked. 

"Well, well. It looks like the mice have returned to the scene of the crime," Shinobu said, her voice icy cold with anger. "I guess that answers the question as to where my latest drug ended up."

She walked over to the four, her form looming over them, while Kanao followed suit. Then, while leaning down and before anyone could move or react, she scooped up all four boys into her hand and went over to the counter, setting them down. 

"All right then. That drug took me three months to work on, only to have it go up in a single explosion," Shinobu continued. "So, naturally, I would like to know who was responsible. And I would strongly suggest you tell me the truth, or else your punishment will be all the harsher." 

Zenitsu immediately pointed at Inosuke. "It was him, Ms. Kocho," he said. "All him. He stole your drug in order to pull a prank on a teacher because he thought it would be funny." 

"You traitor!" Inosuke snapped angrily. "How could you betray me?!" 

"I refuse to take the fall for someone else's crime," Zenitsu spoke snootily. "As a member of the Disciplinary Committee, it's my duty to be honest and report any crimes or violations in this school." 

"Yet, you continue breaking the rules by not dying your hair," quipped Giyu. 

Zenitsu glared while growling, but continued. "And in light of this incident, I strongly recommend that you give him a fitting punishment." 

"Well, I appreciate your words, Zenitsu," said Shinobu. "But I can't help but sense that you've got some ulterior motives. No doubt naughty and lewd ones, knowing you." 

Zenitsu gulped as he broke into a sweat, and Shinobu innocently grinned. 

"You are right about one thing. A fitting punishment is in order," said Shinobu. "But it won't just be Inosuke who will be punished. You'll all receive punishment. All of you." 

Zenitsu's face went pale, as did Tanjiro's. Even Inosuke couldn't help but grow tense. But Giyu bravely spoke up. 

"Wait a minute, Shinobu!" he objected. "We didn't have anything to do with this, so why include us?!"

"And it's not your job to give out punishments!" added Giyu. "As the guidance counselor, that's my job! And what's more, you need to return us to normal, right now!"

Shinobu chuckled as she looked at Giyu. "That drug was something top secret I've been working on, and since you all know about it, that makes you all accomplices, and I can't afford to let this get out, nor will I let it go. So it's only fitting that you all be punished thoroughly. And I think I'll start with you~."

She then reached out, grabbed Giyu in her hand, and turned her back towards the boys. 

"H-Hey! Ms. Shinobu! What do you intend to do with Mr. Tomioka?!" Tanjiro shouted. "Please don't be too harsh with him!" 

But Shinobu paid no mind as she lay Giyu flat on the table, pinning his arms and legs with her hands, giggling coyly.

"H-Hey! Just what do you think you're doing, Shinobu!" demanded Giyu. "Let me go this instant!" 

He struggled to get free of her grasp, but he couldn't. 

"Sorry, Giyu, but you're not going anywhere," said Shinobu. "Now, it's time to take your punishment, so try not to resist." 

She leaned in close, puckering her lips, and kissed his lower body, her lips engulfing it for a good, long pause before pulling back. She would kiss him again, pressing her lips right in the middle of his body, pressing firmly as they engulfed Giyu's body, leaving his feet and his head. 

Giyu's face went red as he felt the weight of her face on his body, leave it, and weigh on it again. "Hey! Knock it off already!" he snapped flusteredly. "Just what do you think you're doing-!"

But Giyu's voice was promptly cut off as Shinobu kissed his upper body. 

As this went on, Kanao watched on with flushed cheeks while Tanjiro and the others could only stare at Shinobu as she wagged and wiggled her hips, while Giyu would occasionally yell before going silent. 

"Wh-What in the world is she doing to Mr. Tomioka?!" Tanjiro cried worriedly. 

"Whatever it is, it must be something horrible!" Inosuke spoke warily. "Something truly agonizing if he's yelling that much!" 

Zenitsu, on the other hand, was staring squarely at Shinobu's butt, watching as it swayed to and fro. His eyes were bloodshot with lust as he let out a shriek of delight as he somersaulted in the air. "This is it! The best seat in the house for a shrunken man! I've never had the chance to see Shinobu's butt before, but now I can die a happy man!" 

"Who the hell cares about her butt?!" Inosuke snapped. "You're talking nonsense again, so shut up already!" 

Zenitsu then glared at Inosuke. "It may not make sense to you because you're nothing but a brain-dead delinquent, but it means everything to me!" he snapped. "But then again, you were raised in the mountains, so it's natural you wouldn't understand anything about the joys of women! I feel so sorry for you, you late-bloomer!"

"What'd you say to me?!" Inosuke glowered in anger. "I'm not a flower, and I know stuff about women!" 

The two then began to argue with each other while Tanjiro stood off to the side, exasperated. 

"They picked now of all times to start fighting?" he groaned. "Can't they see the situation we're in right now?"

Then, Tanjiro heard a gasp come from Kanao, catching his attention. When he looked up, he saw that her face was now filled with shock, her hands clasped over her mouth. In addition, he couldn't hear either Giyu or Shinobu, which worried him. 

He soon found out why. 

Shinobu straightened from where she had been leaning and turned to face the three boys. Tanjiro's face went pale as he let out a scream. Zenitsu and Inosuke, upon hearing him, also looked towards Shinobu and couldn't help but shout in horror. 

While looking at the boys with an innocent and playful expression, the woman now had her mouth closed with a familiar pair of legs sticking out from her lips. Those legs kicked and flailed helplessly as a muffled voice came from inside her mouth. 

"S-Shinobu! What do you think you're doing?!" Tanjiro yelled out. "Spit out, Mr. Tomioka, right now!" 

But Shinobu's eyes narrowed while twinkling mischievously as she smirked. Then, while pursing her lips, she sucked up both of Giyu's legs like a pair of noodles. Then, with him now inside her mouth, she used her tongue to move him to her right cheek, making it swell out to his shape. 

The protrusion moved and squirmed as Giyu struggled inside, while Shinobu giggled as her membrane was tickled. 

"She just straight up ate him!!!" Zenitsu howled in horror. 

"I didn't think she had it in her!" Inosuke gulped. "I knew she was scary, but this just confirms that she's a true monster!" 

"Kanao? Could you do me a favor and handle Tanjiro and Zenitsu for me?" Shinobu asked sweetly. "I can handle Inosuke by myself." 

Kanao let out a squeak as she looked between the boys and Shinobu while worriedly fretting. 

"No, Kanao! Please don't do it!" Tanjiro begged. "You don't have to do as she says!"

"He's right! I may like girls, but there's no way I want to be eaten by one!" shrieked Zenitsu. "Plus, I don't think we would taste good! Particularly Inosuke, because he hardly takes a bath!" 

"I do, too!" Inosuke snapped indignantly. 

"Come now, Kanao. Haven't you always wanted to have Tanjiro to yourself?" Shinobu then temptingly asked her. "You were always so shy when it came to Tanjiro, and have constantly tried to approach him, but to no avail. And even you've grown tired of Zenitsu and his… lewd antics. It's your opportunity to kill two birds with one stone." 

Kanao played with her fingers as she gave a long stare at Tanjiro while he stared back at her with pleading eyes. 

"If you don't, I'll just have all four of them to myself ♪," Shinobu then said in a slight sing-song voice. "And I can be a bit greedy~." 

Kanao's shoulders jumped at this, and she then focused on Tanjiro, nodding silently. Then, she reached out for Tanjiro with her hand.

"No! Kanao! Please, don't!" Tanjiro pleaded as he nervously stepped back. "This isn't right, and you know it!!" 

Kanao wasn't listening as her hand came closer. At that moment, both Inosuke and Zenitsu dashed forward. Zenitsu grabbed Tanjiro by the scuff of his neck and darted in one direction towards the cabinets, while Inosuke went in another direction towards the vials. 

"Sorry, but if you're going to make a meal out of us, you're going to have to catch us first!" Inosuke barked with confidence. 

Shinobu looked across at Inosuke and chuckled as she touched Kanao's shoulder before calmly following Inosuke while she followed Tanjiro and Zenitsu. But as she did, she felt Giyu struggling in her cheek as he moved out of it and onto her tongue. 

"Come now, Giyu. It doesn't matter what you do," Shinobu thought. "You're not coming out~. But it is rather fun feeling you struggle~." 

She then started juggling Giyu around with her tongue while swishing him back and forth between her cheeks like she was sucking on candy. The man screamed while coughing, desperately trying to endure, but Shinobu paid no mind as she soon came to the rows of tubes. Just as she did, Inosuke came poking his head out between two of them. 

She reached out to try to catch him, only for Inosuke to hide behind them, forcing her to hesitate, not wanting to break or knock them over. 

"Let's see if you can catch me now!" Inosuke taunted. "I'm too fast for you!" 

He then kept darting around the tubes while taunting Shinobu mockingly, which made her grow rather annoyed. It was like she was playing a game of wack-a-mole.

But while she was focused on Inosuke, Giyu, from inside her mouth, was able to recover after getting tossed and swished around like laundry in a washing machine. In a moment of defiance and desperation, he thrust out his right arm between her lips using all the strength he could muster, and it, along with his head, emerged from between Shinobu's lips, his skin shining with her saliva as he gasped for air. 

Shinobu looked down in surprise, and as he poked his head out, Inosuke froze from shock. 

"L-Let me go, Shinobu!" Giyu gasped. "I-I'm not your meal, and I won't let you have your way!" 

Shinobu became all the more peeved and was about to suck him back inside of her mouth when she noticed Inosuke staring at her. 

"Thank you, Giyu~," she thought. "You've presented me with the perfect chance~." 

And with quick precision and speed, she shot out her hand and was finally able to grab Inosuke before he had a chance to hide behind the tubes. He struggled as he tried to get free from the woman's grasp, but Shinobu held him tight as she held him right in front of her face, as she smirked with triumph. 

"H-Hey! Let me go!" Inosuke yelled. "I said, let go of me!" 

"Oh, I'll let you go all right~!" Shinobu taunted in her thoughts. "But you won't be going free~!"

She held Inosuke by the back of his uniform and craned her neck upward, dangling him just above her face. Then, she opened her mouth. Because she did, Giyu lost his footing and started to fall, but managed to grab hold of the edge of Shinobu's teeth with his hand, catching himself in the nick of time. 

"I've got to climb out of here before Shinobu closes her mouth!" he gasped. 

Using his strength, despite Shinobu's humid breath blowing against him from below while drenched with spit, he got a good grip of her teeth with his other hand and started pulling himself up to freedom. However, it was then that Shinobu had decided to let go of Inosuke. While screaming and flailing helplessly, he fell right on top of Giyu, which, upon crashing into him, caused him to fall back into the confines of her mouth along with Inosuke. 

Shinobu chuckled as she felt both boys fall into the back of her mouth before closing her lips. With her cheeks now puffed up like a chipmunk's, she once again started swishing the contents in her mouth, sucking and alternating back and forth between her cheeks. More muffled cries from Giyu and Inosuke could be heard, but it was music to Shinobu's ears as she enjoyed herself. 

"This is turning out to be more fun than I expected~," Shinobu thought. "I think I might be into this~."

Then she suddenly remembered Kanao and looked over to see how things were going.

Kanao now stood beside the cabinet, on her tiptoes, reaching with her hands towards Tanjiro and Zenitsu, who were now on top of it, staying well out of her reach. But Zenitsu was hanging on by the edge while Tanjiro desperately held onto him, determined to keep him from falling. 

"No!!! Get away! Get away, you monster!" Zenitsu shrieked as he kicked his legs. "I don't care how cute you are! I'm not going to be your lunch!"

"Stop moving around, Zenitsu!" Tanjiro shouted, grimacing as he bravely held on. "I can't hold you if you keep kicking around!" He looked towards Kanao. "Please, Kanao! I'm begging you! Can't we compromise on another punishment instead of this?! Even you have to admit that this is crazy! You don't have to do what Shinobu tells you to do!" 

Kanao paused for a bit to think, appearing to reconsider, but then she grabbed the sides of the cabinet and started to shake it while keeping her mouth open, using her unnatural strength. 

Tanjiro and Zenitsu screamed with fright as the vibrations rattled them, but Tanjiro clung firmly like a bulldog, refusing to let go. But he could feel Zenitsu slipping from his grip. 

"Tanjiro! You better not let go of me, you bastard!" Zenitsu shrieked angrily. "I may have always wanted to go inside a girl, but through the lower hole, not that one!" 

"How can you be such a pervert even in a situation like this?!" Tanjiro then snapped. "Would it kill you to think of more important things?! And speaking of which, are those two-." 

Then Tanjiro saw Shinobu approaching them, and when he saw that her cheeks were full, a great deal of dread filled his stomach. And sure enough, while giving him a teasing wink, Shinobu opened her mouth, revealing Inosuke and Giyu resting on her tongue. 

Immediately, Tanjiro's face turned pale, as did Zenitsu's, and Kanao looked back at her.

"Inosuke! Mr. Tomioka!" Tanjiro cried. 

"Oh, shit! She got them both!" Zenitsu shrieked.

Both boys looked toward the two, and when their eyes met, they scrambled to make their way out, but Shinobu closed her mouth before they could make their escape as she giggled. 

"Sorry, boys, but playtime is over~," Shinobu monologued internally. "It's time to say goodbye~." 

With a jerk of her neck while closing her eyes, she audibly swallowed, gulping down both Giyu and Inosuke at once. Tanjiro, Zentisu, and Kanao watched as a significant bulge traveled down her throat before disappearing past the collar of her clothes. 

Zenitsu and Tanjiro were horrified, their faces white as sheets.

"N-No… Mr. Tomioka. Inosuke," Tanjiro spoke in a hushed, fearful murmur. 

"S-She ate them," Zenitsu said in a stunned, quiet voice. "She really ate them." 

Then, Kanao suddenly remembered her task and, seizing her chance, gave the cabinet a firm shake, which was enough to make Tanjiro lose his grip and footing. 

Tanjiro and Zenitsu plummeted down from the shelf, falling right into Kanao's mouth, landing at the back of it. The sudden landing made Kanao reflexively swallow in surprise. But as Tanjiro and Zenitsu began to slide down her throat, due to their combined sizes, both boys became lodged in her esophagus. 

Kanao's eyes went wide with panic as her breath caught in her throat, and she struggled to breathe, tapping her chest as she tried to dislodge them. 

"Kanao!" Shinobu cried. "Hold on!" 

Knowing that she was choking, Shinobu quickly rushed to the girl and gave her a few firm pats on her back. Then, Kanao violently coughed, which was enough to dislodge both of the obstructions from her throat.

Tanjiro came flying out of her throat and into her hands, his body slick with her saliva, but miraculously unharmed. 

"That was way too close!" Tanjiro gasped. "For a second, I thought that I was done for!"

Then, he heard a familiar voice yell out from behind.

"Tanjiro! Help me! Don't leave me behind!" 

Tanjiro turned and was welcomed to the sight of Zenitsu, scrambling to get out of Kanao's mouth while reaching out for the boy, but only kept slipping on her tongue. 

"Zenitsu! Hang on!" Tanjiro yelled. "I'm coming to help you!

But as Tanjiro reached out towards Zenitsu, intending to make good on his promise, Kanao's lips snapped shut, sealing the blonde's only hope of escape. The next second, she swallowed. 

Tanjiro then watched as a protrusion swelled up her throat and made its way down it, while the victim inside shrieked and yelled hysterically until his screams disappeared along with his form as he landed in her stomach. 

With him being the only one remaining, now gripped with fear, Tanjiro jumped out of Kanao's hands in an attempt to escape onto the counter. However, Shinobu snatched him out of the air, anticipating his attempt. 

"Not so fast, Tanjiro~," she said. "Surely, you're not trying to run away from your responsibility, are you~? I understand that this punishment may seem intimidating, but like everyone else, you must take your punishment like a good model student."

"You're just being completely unreasonable, Shinobu!" Tanjiro snapped as he thrashed around. "Put me down right now!"

But Shinobu wasn't listening as she held him up to Kanao. "Now, open wide~," she said to her. 

Kanao did so, sticking out her tongue, and while Tanjiro was still struggling, Shinobu fed him to her, closing her mouth as soon as he was inside it. Tanjiro yelled out from inside her cheeks, but her lips held him firmly inside while her cheeks undulated and moved. 

"You'd better swallow him now while you have a chance, Kanao," said Shinobu. "I wouldn't want you to end up choking again." 

But Kanao shook her head, squeaking cutely.

Shinobu was puzzled while taken aback. "What? You don't want to swallow Tanjiro?" she questioned. "But why not?" 

Kanao looked at Shinobu, who was playing with her hands, appearing to be silently appealing to her. 

Shinobu then frowned. "Let me guess. You don't think Tanjiro deserves to be swallowed, so you want to go easy on him." 

Kanao timidly nodded. 

Shinobu then smiled in understanding. "Oh, all right. I suppose I can go easy on him," she decided. "Plus, I think I can make good use of him." 

Kanao's eyes lit up as she smiled in gratitude before opening her mouth and taking Tanjiro out of it. 

"You should count yourself lucky, Tanjiro," said Shinobu. "I've decided to be a bit more lenient with you per the request of my darling sister. And I could use a good test subject for making the reverse drug to return you all to normal. Aren't you a lucky boy~?" 

Tanjiro couldn't speak, but was somewhat relieved. 

Shinobu then went over to the counter and grabbed some glass tubes. "Now then, I'll go ahead and get started. Until then, make sure you keep an eye on Tanjiro, Kanao~." 

Kanao nodded as she held Tanjiro close, nuzzling her cheek against him like he was a cute pet. But as she did, both she and Tanjiro could hear Zenitsu's hysterical shrieking coming from Kano's stomach. 

"Let me out of here! It smells like crap in here, and it's hot and humid! I don't want to die in here! This can't be how it ends!" 

Kanao's cheeks redened with embarrassment, while Tanjiro could only stare, growing all the more worried. 

"How in the heck did I get into this mess?" Tanjiro bemoaned miserably. "I don't know how things can get any worse." 

But then he started thinking about the explosion from before, which made him wonder about something. What if there were other victims of Shinobu's drug? The thought of it made him feel a sinking feeling in the pit of his stomach. 

"Somehow… I get the feeling that things might be going worse for others, too. Let's just hope that I'm overthinking it."