Work Text:
"Dazai, when's your birthday?"
Dazai looked up at Atsushi from the paper airplane he was making out of the paperwork he was supposed to be doing. Atsushi had no doubt he was planning on throwing it at Kunikida, who, based on how tightly he was gripping his pen, had already recieved way more than his daily dose of Dazai's shenanigans.
"What brought about that question?" Dazai asked in return, eyes sparkling with mirth.
"I'm just curious," Atsushi said. He knew Dazai hated that sort of vague answer, but the chances of an honest response from Dazai would be significantly lowered if he knew the real reason behind Atsushi's question.
Last month, on Atsushi's birthday, the detective agency had a small celebration. Everyone had gotten him a gift (a tiger plushie from Kyouka, a stationary kit from Kunikida, and so on). Fukuzawa brought in a cake (which Ranpo ate most of), and everyone talked and danced for hours.
Atsushi had been over the moon at the thoughtfulness of it all- it made him so happy to be appreciated by the people he cared about the most and to be reassured that he deserved it. He wanted to do the same for Dazai. He knew how important the agency was to him, and, like Atsushi, Dazai's birthday was never celebrated in the past. A surprise party would be the perfect present.
There was just one problem, though, and that was Dazai himself.
He was the most secretive person on the planet. Even the most mundane details took forever to coax out of him, and he never willingly volunteered information about himself.
So, Atsushi had to be tactful. He hated lying, but he didn't want to spook Dazai with the true nature of his question in fear of getting brushed off or shut down.
Dazai contemplated for a moment, humming softly. "It's a secret," he said with a giggle.
"How come?" Atsushi asked. "You know when my birthday is. Probably everyone else's, too."
"You're right about that." Dazai smirked. "Let's see... Kunikida's is August thritieth, Kenji's is August twenty-seventh, Ranpo's is October twenty-first-"
"Hey, that wasn't an excuse to start listing off everyone's birthday!" Atsushi scolded, poking him playfully. "Quit changing the subject, Dazai."
"Oh, was I? I didn't notice." he laughed. He made a few more folds on his paper airplane and held up the finished product. "Hey. How much do you wanna bet this hits Kunikida square in the glasses?"
Ah, so Atsushi was right about that. Figures. "Zero yen. I'm not entertaining this."
Dazai stuck out his lower lip in a playful pout. "Aw, zero yen? Your faith in me is so low," he tutted. Then he reeled his arm back and threw the paper airplane with deft precision. It ended up poking (a now very irritated) Kunikida in the forehead. Dazai mumbled something about "missing the glasses" before he was being pummeled with disciplinary remarks from Kunikida.
Atsushi sighed. Dazai was truly hopeless- it looked like Atsushi would have to seek help if he wanted to fulfill his mission.
"Hi, Yosano!"
The woman in question was sitting in her medical office, examining a scalpel. She smiled when she saw Atsushi standing in the doorway.
"Hey, Atsushi! Come on in."
Atsushi did as directed, walking in and sitting down in another chair. Yosano looked him up and down.
"So, what's going on? Pulled a muscle? Sprained your wrist? Maybe even a fracture?" There was a glimmer in her eyes as she spoke, and the way she was holding her scalpel made Atsushi scoot back his chair a bit.
"Erm, I'm not here for medical assistance." Atsushi scratched the back of his neck. Yosano seemed to slump a bit, but she put the scalpel down (much to Atsushi's relief).
"Oh, okay. Did you wanna talk about something?"
"Yes, I did." Atsushi nodded. "Do you know when Dazai's birthday is?"
"No, I don't think so." She shrugged. "Are you trying to get him a gift or something?"
"Kind of," Atsushi said. "I wanna throw him a surprise party."
"Oh, that's pretty sweet of you!" Yosano commented. "Like how we did on your birthday, right?"
Atsushi grinned. "Yeah, exactly like that. I tried asking him about his birthday earlier, but he was totally evasive."
"That's Dazai for you." Yosano chuckled fondly. "I don't think you'd get it out of him even if you held a knife up to his throat." She glanced at her scalpel. "Hey, maybe we should try that!"
Atsushi looked rather startled by the doctor's suggestion. "I'd rather not, thanks..."
"Eh, suit yourself."
Atsushi shook his head, grinning a little at Yosano's antics. "I'll get going now. Thanks for chatting with me, Yosano!"
"You're welcome," Yosano said as Atsushi got up to leave. He waved goodbye, walking to the door. Right as he was about to leave, Yosano called out to him.
"If you sustain any injuries, be sure to let me know!"
Atsushi gulped; she was holding the scalpel again.
"You wanna know when Dazai's birthday is?"
Atsushi nodded at Kenji, who'd been leading his cow down the hallway after she'd been kicked out of the office area by Kunikida. Apparently, paperwork looked a lot like grass to cows, leading to a significant dent in Kunikida's well-organized stack.
"Yeah, I was hoping to throw him a surprise party."
"That sounds awesome!" Kenji beamed. "Can I help you plan it?"
Atsushi chuckled. "Of course! But we can't start planning until we know when to plan for."
"Oh, yeah!" Kenji said. "Right. Well, I have no idea. Hey, maybe Hanako knows! Hanako, do you know when Dazai's birthday is?"
Hanako simply moo'd, flapping her tail. Kenji sighed.
"She says she doesn't know."
"...Thanks anyway."
The next day, Atsushi knocked on the door of Fukuzawa's office. A call to come in was bellowed, and Atsushi went inside.
"Good morning, Atsushi," Fukuzawa greeted, pushing some folders to the side.
"Good morning, president." Atsushi sat down in the chair in front of the desk. "I was wondering if you had a moment to talk."
"Certainly," was the reply, as Fukuzawa clasped his hands together. "What is it that you'd like to talk about?"
"I've been trying to find out when Dazai's birthday is, because I want to throw him a surprise party," Atsushi explained. "I've asked around a lot, but nobody seems to know. I figured that, since you're the president, maybe he told you."
Fukuzawa thought for a moment, then shook his head. "I'm sorry, Atsushi. I don't recall him ever disclosing that information."
"I see... could his birthday perhaps be on file somewhere?" Atsushi suggested. It felt wrong to find that out by snooping in Dazai's personal files, but drastic times called for drastic measures- a surprise party was at stake here.
"I doubt it," Fukuzawa said. "His records are so well-hidden, it would be impossible to find."
"I see." Atsushi deflated. "Well, thank you for your time, President Fukuzawa."
"Of course." Fukuzawa nodded. "I wish you luck in this endeavor of yours. Truly thoughtful and persistent people like you are hard to come by."
Atsushi smiled, feeling warm inside from the compliment. "Thank you, that means a lot to me."
The two said their goodbyes, and Atsushi walked into the agency once more.
Dazai wasn't at the agency the next day.
Atsushi hoped it was just to blow off work and not for any severe reason (with him, you could never be sure). However, he was grateful for Dazai's absence, because it meant Atsushi got to ask someone he couldn't have before. Someone who was constantly pranked by Dazai, someome who constantly tried to whack the laziness out of him, whether it be with words or his notebook. Someone who was Dazai's partner, his friend.
Atsushi walked up to Kunikida's desk with a determined smile. Kunikida glanced up, wrote one last word on the paperwork he was filing, and set his pen down neatly.
"Hello, Atsushi."
"Hi, Kunikida," Atsushi said. "There's something I want to ask you."
Kunikida raised an eyebrow. "And what is it?"
Here goes nothing. "I want to throw Dazai a surprise birthday party, but I have no idea when his birthday is. Do you know?"
Kunikida shook his head. "No, I can't say I do."
"Really? But you're his partner. Surely he must've told you at some point."
The other man sighed. "Dazai and I are partners, yes. Despite my... constant annoyance with him, we have a good bond. That bastard's a talker, but never about personal information."
"Damn it," Atsushi grumbled. "I can't believe nobody knows."
"Maybe there's a reason for that."
"Huh?"
Kunikida shrugged. "He probably didn't tell anyone his birthday because he doesn't want anyone to celebrate it. Or rather, because he doesn't think it's worth celebrating."
"I did think about that," Atsushi said, "But that's exactly why I want to do this. I want to show him he's worth it, and that we really care about him."
"I'm sorry, Atsushi." Kunikida sighed regretfully. "I'm afraid you're going to hit a dead end with this. There's no way anyone knows when his birthday is-"
"June ninteenth."
"Pardon?"
Kunikida turned his head to the source of the voice. Atsushi followed his gaze to find Ranpo sitting cross-legged on his desk, sucking on a lollipop. He slid it out of his mouth and grinned.
"That's his birthday," he said. "June ninteenth."
"Really?" Atsushi smiled brightly, but Kunikida was a bit more cynical.
"How are you so sure?" He asked. "Did Dazai tell you?"
"Nope!" Ranpo chirped. "Just a hunch."
"I think we're going to need a little more than a hunch."
Ranpo scoffed, "C'mon, when have I ever been wrong?"
Kunikida was silent; Ranpo had a point.
"I don't think you ever have!" Atsushi said. "Thanks, Ranpo."
"Anytime!" Was the enthusiastic reply, before Ranpo busied himself with his lolipop once more.
So, June ninteenth it was, then. That was less than a week away, and there was a lot of work to be done. Atsushi turned to Kunikida with a huge grin.
"Hey, Kunikida, I'm gonna start planning the party. Do you wanna help?"
Kunikida huffed. "I still have a bit more work to do." He pushed up his glasses, then his expression melted into a smile. "But, once I'm done... I'd be happy to assist."
It was the day of the party. The room was almost fully decorated; Kenji was showing Kyouka how to put up the last of the streamers. Yosano and the Tanizaki siblings were setting up the snack table (read: guarding it so Ranpo couldn't devour all the snacks before the party started). Everyone else was just standing about and talking, waiting for the party to begin.
"I never thought I'd say this, but thank goodness Dazai decided to be late for work today," Kunikida said, getting a laugh out of Atsushi.
"Yeah, it would've been pretty awkward if he came in while we were getting things ready," Atsushi agreed.
"If he doesn't come in soon, I'm going to eat his cake," Ranpo chimed in.
"Ranpo, don't you dare," Kunikida chided.
Ranpo pouted. "Hey, I'm technically the reason this is even happening, remember? I should be allowed to eat the cake."
"And you will get to eat the cake." Atsushi laughed. "But you have to wait, alright? Dazai's not even here yet-"
As if on cue, the door opened and Dazai stepped inside. Shock was evident on his face as he surveyed the decked-out office area, closing the door behind him.
"Surprise!" Everyone shouted in unison. "Happy birthday, Dazai!"
Dazai's eyes widened, like they couldn't believe what they were seeing. He stepped further into the room. "You guys really did all this for me?"
"Yeah!" Kenji nodded enthusiastically. "We all helped plan it, but it was Atsushi's idea!"
Dazai looked over at his mentee, shooting him a quick smile. Atsushi grinned back from ear to ear.
"Wow, I really don't know what to say." Dazai giggled. "Thank you all so much!"
After that, the party kicked off in full swing. Pop music played in the background as everyone laughed, played games, and had a good time. Ranpo was finally allowed to eat some of the cake, which he was very happy about.
At some point, Atsushi went over to the punch table to get a refill and some snacks. Not long after, a voice sounded from behind him.
"So, now I know why you were asking me about my birthday a few weeks ago."
Atsushi turned to see Dazai holding his own cup of punch.
"Yeah, you got me." Atsushi chuckled.
"However did you find out, I wonder?" Dazai asked with a small smile.
"Ranpo."
"Ah." Dazai nodded in understanding. "That man is too smart for his own good."
"That he is," Atsushi agreed. "Are you having fun?"
"Yeah, I am," Dazai said with a soft genuinity that was seldom heard from him. "All of this, it's... made me really happy."
Atsushi beamed. "Good, I'm glad. Everyone here cares about you, and I thought this would be a nice way of showing it."
Dazai's eyes widened for a moment, but then he smiled, warm as the sun's rays. "Thank you so much for doing all this."
"You're welcome." Atsushi laughed gently, raising his cup for a toast. "Happy birthday, Dazai."
The two clinked their cups together and drank. A sweet silence enveloped the corner, broken by Dazai's mischevious voice.
"Hey, Atsushi. Do you think anyone would notice if I spiked the punch?"
Atsushi rolled his eyes fondly. Leave it to Dazai to spoil a moment like that. It was okay, though- Atsushi had a feeling that, as Dazai opened up further, they'd have even more of them.