Chapter Text
The soft summer breeze rustled the trees—the only gentle sound in the UA forest area at 6:30 p.m. The air crackled with the green lightning emanating from Izuku’s body and rippled from the heat of Kacchan’s blasts. They’d been going at it non-stop for half an hour. As third years in their second semester, they needed to be on top of their game and as always, they were each other’s best challenge. So, what did they do? They sparred until they were left with heaving breaths; until their bodies were so sweaty their scents would mingle due to the exchange of blows; until they felt that deep sense of satisfaction and that boost of serotonin that left them both with tired smiles, bumping off each other as they walked back to the dorms. However, they did not get a chance to get that far that day.
Izuku used blackwhip to throw the blond against a tree, but his opponent was as quick as always and created a blast to avoid the collision. Kacchan landed safely on his feet before shooting an AP blast that would have at least grazed Izuku were it not for the blinding light that unexpectedly enveloped the area.
Struggling to clear his vision, he called out for his childhood friend—his crush really, but no one needed to tell him that. “Kacchan!”
No response.
Izuku’s heart was beating frantically, memories of their first year when Kacchan was abducted came rushing back.
Desperate, he tried again, louder as he cupped his hands around his mouth. “Kacchan!”
Complete silence. The light was still much too bright. What the hell is that?
Tears began to pool in his eyes. “Kacchan, are you okay? Please, answer me!”
He heard a growl and a grunt—at least he’s there. The light began to dim, and Kacchan’s gravelly voice answered, “Yeah, Deku, I’m fuckin’ fine. It’ll take a stronger hit than that to knock me out; you should know your mate better than that.”
Izuku froze. The voice was Kacchan’s, the vocabulary was Kacchan’s, but that was definitely not Kacchan.
Mate? Izuku turned bright red at the word, but shook it off, his worries for Kacchan’s safety overriding his flustered thoughts. Finally, opening his eyes, he saw a man that had Kacchan’s face, but he was more muscular, taller, tattooed, and pierced, and his clothing...this man was not from this world.
He saw the moment the other man noticed that he was not the Deku he knew.
“Who the fuck are you? Where’s Deku?” the blond man asked with a snarl, sniffing the air around him.
Weirdo. “I should ask you the same thing!” Izuku answered. “Where’s Kacchan?”
The man’s snarl dropped and he tilted his head in confusion, narrowing his eyes as he slowly said, “I’m Kacchan; that’s what Deku calls me.”
Izuku now mirrored the man’s movements. “I’m Deku; Kacchan gave me that name when we were kids.”
Their eyes widen in realization. This Katsuki, because Izuku will not call this other guy Kacchan—that’s way too confusing—echoes his thoughts.
“Holy fuck. We switched!”
Izuku felt his anxiety rise, his breath quickening. He wasn’t even aware he’d started a torrent of mumbling until he heard a fond chuckle that made him stop cold in his tracks.
“I don’t know if it’s a quirk, nerd,” the blond said, “You two really are the same,” shaking his head fondly.
Izuku took a deep breath and let out a nervous chuckle as he ran a hand through his damp curls. “You know what quirks are?” Seeing the other man nod was enough for him to continue. “Okay, okay. We need to think. You clearly look like Kacchan, but you’re also a foreigner. Crap, how are we going to hide you? Or should I tell Aizawa-sensei-”
“Deku,” the man purred, and Izuku felt a warmth pool in his nether regions.
‘What was that?’
He’d always thought Kacchan’s voice was sexy, but his Kacchan had never spoken to him in that tone. So gentle, and so alluring.
Ignorant to Izuku’s inner dilemma, Katsuki continued, “Listen, love, your Kacchan will be back soon, and I’ll go home to my mate. For now, let’s just return to our den, yeah?”
“Our den?” Izuku asked. “Do you mean where we live?”
The man huffed. “Yeah, what the fuck else would I mean?”
“Oh, okay. Well, we live at our school—do you have schools where you're from?”
“Of course we have schools! I’d be a terrible king if I didn’t provide an education for my people.”
“King? Wait, don’t answer that yet. Let’s just get back to the dorms. I’ll take you to my room first, we’ll figure out what to do, and then I’ll show you where to sleep and find Kacchan’s things.”
That earned him a smirk, and he almost swooned on the spot. Izuku wasn’t sure how he’d survive this. He hoped whatever time travel or dimension quirk’s effect caused this switch only lasted a couple of hours.
“Sounds like a plan, Deku. No matter which version of you, you’re always strong and resourceful, ain’t-cha?”
Praise from someone who looks and sounds like Kacchan? Izuku wasn’t surviving this, no way.
He laughed nervously. As he began walking, he let out a most embarrassing squeak when Katsuki took his hand. He tried to focus on his breathing. He couldn’t. KATSUKI-FUCKING-BAKUGOU WAS HOLDING HIS HAND! It was a dream come true—if only it was his Kacchan. He let out a sigh of disappointment. The other man looked at him with concern, but kept quiet.
Luckily, most of the group was out on internships or at the mall—Kacchan, Kirishima, Mina, and him were going the following weekend due to their schedules—so it was easy to sneak in. This Kacchan's footfalls were silent, and he took the initiative to check if anyone was around on most turns.
Once in their room, he managed to release the breath he’d been holding since they entered the common room, only to suck it back in when Katsuki hugged him. Izuku was as stiff as a board, unsure of what was going on.
“Um, Katsuki, what are you doing?”
“Who the fuck is Katsuki? Just call me Kacchan too. It’s fucking weird to hear your face call me that outside of our furs.”
“Furs?”
“Bed, nerd”
“B-bed?! We sleep together?!”
Katsuki shot him a hungry look, licking his lips as his eyes roamed over Izuku’s body. “Oh, we’ve done a lot more than sleep.” And just as the look came, it went. “But that’s not what we need to talk about right now,” he began, adjusting his pants.
Was he...aroused? And did he just imply-
“We need to get our story straight if you want me to pose as your Kacchan, but I need to know a little more about your world to do that.”
Izuku’s head was spinning—too many new things. This Katsuki was nice, respectful, turned on by him, and apparently they’d done things. Still, Izuku’s curiosity for the unknown was quite present, so he shot Katsuki a beaming smile and said, “Of course! Let’s take a bath though. You can go first.”
Katsuki looked at him weirdly, but nodded. Izuku patiently showed him how to use the shower, then waited. However, he forgot one important detail: clothes. So, when Katsuki came out in his full, naked glory, Izuku choked and felt his face flush, averting his eyes as he searched for a pair of boxer briefs to give the guy. He wasn’t not sure how he managed, the sight of Katsuki’s tan, taut muscles were heavily distracting. He didn’t even want to think about certain, well-endowed areas that he promised not to stare at. Luckily, since Izuku’s hips are larger than Kacchan’s, the boxer briefs seem to fit Katsuki, although the guy didn’t seem too happy about it—he’d been pouting ever since Izuku managed to look up. He knows he won't be able to unsee all that.
The blond automatically went to lay on the bed, so Izuku, holding on to a sliver of common sense, sat on his desk chair.
“Should I go first?” Izuku asked.
Katsuki shifted to rest his head on his palm. “Yeah, I like hearing your voice.”
Izuku tried to ignore the heat that’s rising to his face, and began. “You should know that Kacchan and I were childhood friends, but after we found out I was quirkless, he decided that I wasn’t good enough to stand by his side and he became my bully. At one point, it was so bad, he told me to kill myself; I knew he didn’t mean it though.” He heard Katsuki growl and curse under his breath, but continued.
“I did end up getting a quirk, and we both got into our dream school hero school: UA. Here, Kacchan made real friends: Kirishima , Mina—he calls them Shitty Hair and Raccoon Eyes,” he was going to go on, but Katsuki interrupted.
“-and let me guess, an annoying blond I call Dunce Face; and a tall lanky guy I call Soy Sauce face.”
Izuku’s eyes widened. He let out a sign of relief and then nodded with excitement, “Yes!”
“And the one who gave you your power, is the warrior—hero—All Might?”
“That’s-That’s right! You have an All Might?!”
Katsuki chuckled, “Yes, we do, but he’s your step-father in our world.”
“Oh, wow! Okay, okay, I have so many questions, but I need to finish first.”
Katsuki smiled softly at him and nodded. Izuku’s heart skipped. Why was this version so different from his? He loved Kacchan, but what he wouldn’t give for one look like that.
Izuku went on to tell him about their hero experiences. He started with the trauma from the kidnapping, the League of Villains, and Shigaraki. Then, how they found Dabi was a Todoroki; how the three of them helped each other heal. Finally, how they’re considered the big three this year, serving as mentors for the new students.
“And my other self, he treats you better now?”
‘Not as good as you treat yours’, he thought before saying, “We’re friends again, still rivals, but it’s nice. We were training together when the switch happened.”
Katsuki hummed. “Well, our relationship is much different where I’m from, and so is our world, but I guess I’ll start with that. I’m King Katsuki Bakugou, ruler and warrior of the dragonborn.”
“It’s so cool that you’re a king! It makes sense, though.”
“My Deku is also a warrior, but he’s a healer as well. He was trained by his mother in healing practices throughout much of his early years. When he turned twelve, he was taken away. I was devastated. We would always meet in a clearing where our territories met, and one day, he just didn’t show up. I went to his mother’s hut, her eyes were swollen from crying, and she told me that he was taken as an apprentice by a well-known warrior. I was enraged; I felt abandoned, but that was stupid of me,” he chuckled. “Deku never had a bad bone in his body.”
Izuku’s eyes lit up at hearing Katsuki’s tale of his world, but it was strange for Izuku to notice the parallels. The time spent away, the misunderstanding, how his mother had worked to heal others.
“At the time, I was a prince, still ignorant, much like the—‘middle school, did you call it?’—me you described. I was quick to anger, gave harsh replies, and was even harsher during training.
Being without Deku changed me. I decided that it was my fault Deku had decided to leave. I might have met him every day, but I always teased him, pushed him away; I only challenged him, but never told him what that meant. Our customs were different, so while I thought I had been clear with my intentions, his mother had explained that those would have been perceived as friendly gestures alone; therefore, while I thought Deku had been responding to my advances, he had merely been thanking me for my friendship.
‘I took it upon myself to learn about the customs of neighboring kingdoms to avoid miscommunication; to be more understanding of the people around me, to not drive them away. At night, Eijirou and Mina, my closest friends, would help me search for him. It took two years for us to be reunited, and when we were, it was in the middle of battle.”
Izuku chuckled. “Of course, where else could you meet?”
“Yeah,” Katsuki continued with a slight upturn of his lips. “He was beautiful, stronger, his scent just as intoxicating as always. We fought side-by-side, and the training he had received really shone through. No longer was he the scrawny healer I felt the need to protect; he was my equal.”
Izuku’s eyes widened, the word, ‘equal’, on repeat in his brain as the blond continued.
“Our enemy, All for One, was seemingly unbeatable; our comrades had fallen, and my quirk was exhausted; however, Deku had one more idea that would lead us to victory. He said, ‘Kacchan, I’m not sure if this will work, but I need you to trust me,’ and held out his hand.
“Despite the hurt in my heart, I could never deny him anything. I accepted his hand and let him lead mine to the handle of his sword. In a flash, the sword split; I held the other half. Green electricity crackled around him, while fire enveloped mine. With one last cry for victory we fought and defeated the villain. After that, I asked Deku to return home, and he did. We’ve been ruling as a team since then.”
Izuku couldn’t help the tears that spilled. “That’s such a great life,” he smiled. “I’m so happy you two were reunited and that you have such a good relationship. I’m even more sorry that this split you apart.”
The greenette had closed his eyes, and was startled when he felt a thumb rub at the tears on his cheek. “It didn’t. Your Kacchan is an idiot if he did not take the same chance. Are you telling me he almost died for you, you almost died for him, and he’s still denying you two of that life? If I ever meet him, I’ll make sure to change that. I’ve seen some of our past lives; we’ve always been together, Deku.”
“No...don’t. I really don’t think my Kacchan sees me that way.”
“How can he not? Have you not been listening, my love. Katsuki Bakugou will always love Midoriya Izuku; that’s our fate, always has been. I know your Kacchan feels that way, because I am him, Izuku.”
The use of his name stunned him, but the tenderness of the other’s words just made him curl around himself and sob harder. It could never happen. Why was this happening now? He was fine being friends with Kacchan; he didn’t need to know things were better in another world, didn’t need the crippling pain that crushed his heart at the moment. “You’re too cruel, Katsuki.”
“I don’t mean to be; I was just telling you about my life. And it’s too weird to hear you call me that, please.”
Izuku realized that the blond before him spoke the truth. The man had just been doing what Izuku had asked; it wasn’t his fault that this world’s Kacchan broke those patterns, nor was it his fault that he was separated from his love. He must be hurting too. It wasn’t fair to do this. Izuku felt embarrassed. He took a deep breath, gave a resolute nod and wiped away his tears. “You’re right, Kacchan. It’s not your fault. You’re being too nice, and I think that it just caught me off guard. Friends?”
Katsuki smiled, and that was enough reward for him. They settled into comfortable conversation for a while. Izuku showed him what All Might looked like in this world, and had the pleasure of seeing Katsuki’s reaction to television. The two settled on Izuku’s bed to watch the movie in comfortable silence.
It was great—until Izuku tried to take Katsuki to Kacchan’s room.
“No.”
“What do you mean ‘no’?"
“I don’t sleep alone.”
Izuku looked at him incredulously. “Is this normal in your world?”
“What the hell, Deku, didn’t you listen? Of course, it’s normal!” The blond was getting agitated. This seemed more like the Katsuki he knew.
“Well it’s not normal here! What if someone sees you?”
“Then they’ll be jealous, I guess. Who cares?” The crimson-eyed man threw the blankets over himself. “I’m sleeping here, Deku.”
“Wh-Kacchan, no!”
But the other simply turned around and ignored him. With a huff, he took a pillow and some blankets and began to leave, letting a yell escape his lips when Katsuki threw him over his shoulder and then onto the bed.
“I don’t sleep alone, Deku,” he growled.
Izuku’s hands shook—whether from arousal, fear, or nerves, he couldn’t tell. Katsuki ignored his panic, covered them both with the blankets, and curled around him. He was so close—too close! Izuku felt the other’s body press against him and stiffened; the man was a furnace. Was this his new fate? Never to sleep again because a bigger, stronger, more affectionate Katsuki wanted to be near him. Oh, well, at least he’d die happy, surrounded in that caramel scent. Katsuki was lightly purring, something that should’ve been weird, but once again, felt oddly comforting.
He isn’t sure when sleep claimed him, but it was the best night’s sleep Izuku had ever had.