Unendlichkeit

https://archiveofourown.org/works/86281911

This is set only a month or so after the two have met (I said their friendship moved quickly) when Shin turns 15.

(Not beta read or anything, I kinda rushed this)

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Natsuki huffed and threw his phone behind him, ignorant of how close it came to nailing Shin square in the face from where he lounged on the tallers bed.

"Watch it Natsuki!" Shin cried in response, throwing a pillow his way in return.

Natsuki caught it with a chuckle, twirling around in his chair to face Shin as he hugged the projectile against his chest.

"What's got you in such a mood anyway?" Shin puffed, rolling onto his front and pouting.

"Some kids in my class are trying to drag me out for someone's birthday party tonight. I really couldn't care less about it though." Natsuki replied, sliding further down his desk chair.

"Birthday party?" Shin hums, cheeks squishing against his forearms, "like where you burn different chemicals?"

"Wh-" the words nearly choked Natsuki as he tried to find something to say. "N-No, that's not… that's not what you do at birthday parties Shin."

Shin sat up with a quirked brow, seeming skeptical, "that's what we did in the lab," he began slowly, "the old man would burn different chemicals and the fires would all burn cool colours while the scientists sang."

Natsuki took a slow breath as he processed the explanation, a hand coming up to scratch at his scalp. "I mean, I guess if you had fun…" he paused, "Shin, when is your birthday?"

"Oh, um… June seventh," he replied absently, having gone back to taking up the entire bed like a comfortable house cat.

"Seven- Shin that's next week!"

"Hm? Oh, I guess it is?"

Natsuki was taken off guard by Shin's blasé attitude towards the topic. It's not like the Seba family exactly made a big deal out of birthdays either, but with Mafuyu being a spoiled brat, he was used to at least one person pulling on his sleeve asking what he was getting that year.

He supposed Mafuyu only acted that was because of him, though, so it made sense that if the lab didn't kick up a fuss about birthdays then neither would Shin. But that didn't stop the uncomfortable feeling settling in Natsuki's chest.

—

Natsuki could only scrounge together enough free time to buy a cake and some bunting, but the colourful paper he'd cut up and scattered around his bedroom helped a little bit.

After Shin told him his birthday, he'd offered a small hangout in his bedroom again. Getting the visitor permit was a nightmare as always, but it was the only time he was grateful for his good grades.

He gave his room one last glance, cringing a little at the cheap display, before pocketing his handmade party popper and heading out to collect Shin.

The blond waited for him at the airport like always, nothing but a small bag that carried his toothbrush and pyjamas. Natsuki always hated that little bag, the rough canvas that contained Shin's entire life.

When he got close enough, he grabbed Shin by the wrist and started pulling him, much to the blond's protest.

"Natsu- what are you doing? I can walk on my own!"

Despite his attempts at escape, Natsuki's grip was steadfast as he pulled Shin away from the now curious eyes that trailed them.

By the time they'd reached Natsuki's dorm, he couldn't even deny the volume of his heart as it slammed against his ribs. He'd been repeating gibberish in his head for the whole walk, unwilling to reveal even a single detail before the surprise.

He fished his keys out of his pocket, slipping the party popper up his sleeve as he did. As soon as the door was open he pushed Shin inside, ignoring the aggrieved huffing and hawing coming from the older teen.

"Can you get the lights?" He tried to ask casually as he closed the door behind him, bathing the room in black.

Shin grumbled, but complied nonetheless, flipping them on only to freeze at the sight before him.

Natsuki hastily pulled out the popper, tugging the cord to release the confetti inside with a "bang!"

Shin jumped at the noise and whirled around, eyes wide and chest heaving. His eyes scanned the area, taking Natsuki in with a weary sigh, "what the hell was that?"

"Um, a party popper," Natsuki replied lamely, suddenly feeling rather embarrassed. Of course the kid who dealt with guns for a living would be scared of sudden loud noises, how stupid could you get?

Natsuki swallowed as he stuffed the offending object back in his pocket and grabbed Shin's hand, pulling him further into the room. His thumb carved a gentle crescent across the others knuckles in an attempt to sooth the slight tremor.

"Um," he pulled out a lighter, quickly sparking it and hovering the flame above the candles sat in the cake. Once lit, he held it in front of him with an attempted smile, "I'm not singing, but, happy birthday Shin."

Shin stared in complete awe, fire reflecting beautifully in his eyes as he processed everything that had happened. The cake was simple, but still looked delicious. Shin couldn't remember if he'd ever eaten a full cake before.

"What is this for?" He asked quietly, hands wringing the front of his jacket.

"You blow out the candles and make a wish," Natsuki explained patiently, moving to place the cake atop his desk, "I guess the scientists weren't too far off with that fire thing," he chuckled lightly.

"What do I wish for?" Shin asked quietly, almost sounding like a child.

Natsuki held his hand again, linking their fingers slowly, "whatever you want. You can't tell me though, or else it won't come true."

Shin nodded in earnest, eyes set as he leaned down and blew in one confident motion.

Natsuki could take a guess as to what the wish was, something involving the mysterious assassin that Shin seems to love despite it all. Maybe he wished for him to come back, to whisk Shin away from the assassin world entirely. Maybe he wished to never have to go near the JAA or JCC ever again. Maybe that didn't matter.

For now, Natsuki put the thought behind him and started to cut the cake.

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I wasn't gonna make this angsty but I'm afraid it comes naturally to me

I won't be able to translate this for every bday just bc of the sheer frequency at which these come out along w all the other events but this one was very cute and I'm sick in bed anyway so enjoy

HAPPY BIRTHDAY SHINNN RAHHHHHHH💥💥💥💥💥💥

(The art was lowkey rushed mb)

(pls ignore Mrs. Sakamoto's eyes🥹)

i thought the order was supposed to be tough?!

07.06 - Happy Birthday Shin!!!

Based on the new sakapuzz cards