Sixfold Adventures: A Collection of One-Shots

18!Brothers and 17!Sister!Reader

(This was partially inspired by a 'what if' thought in my head while watching the Osomatsu-san movie again.)

When I started attending high school with my brothers, I thought about all of the typical cliches that could happen. Since I was a year younger than them and they were clearly more popular than me (after all, sextuplets were rare), I braced for the girls in their year and mine to flock to me, grasping for the small opportunity that I presented to get into a relationship with them.

After all, if you start hanging out with your crush's sibling, then it's an easy win...right?

It happened a few times as some of their classmates asked me about why they act in unison so often, but I slowly noticed a rift start to pull my brothers' closeness apart. During the first few months of my first year, they had started to shut down and branch away from each other, both at home and school.

Things that we used to do together as siblings crumbled away, leaving me with more free time than I ever wanted -- so I focused on my studies. If my older brothers wanted to spend their last year in high school finding themselves, then I'd aim for something that wouldn't get in their way.

I never really knew how bad the rift had gotten until a few days before their graduation.

"(Y/n)?"

"Come in," I pulled the headphones off of my ears, settling it around my neck as the video game soundtrack continued playing. Partially turning my head, I watched as the guest knelt on the ground facing away from me to close the sliding door behind them. I knew who it was by the curve of their back, "Todomatsu...you should be asleep."

"I can't..." His voice had shifted into a higher pitch over the last year, sounding almost childlike while his demeanor had transformed with it. The youngest of my sextuplet brothers crawled over to me on all fours, only stopping when he was right next to me. The floor desk I used allowed him to lay down and rest his head against my left upper leg, his hands curling up and gripping the bottom of my shirt tightly like a toddler frightened of the dark.

"...I'm almost finished with studying. Be patient for a little bit longer, okay? Then I'll listen to you," I focused back on the science homework before setting my mechanical pencil down and turned off the CD player, pulling the headphones from my neck and resting it on the desk.

The digital clock readout showed '01:03' and -- if Todomatsu's issue wasn't small -- I was going to be up for at least another hour.

"What can I do for my eighteen-year-old brother?"

"I want to hear you sing again," He glanced up at me, his eyes wide with either anticipation or apprehension.

"Todo...I can't sing right now. It's late enough where I'd wake everyone up," I motioned towards the clock. His eyes welled with tears as the corners of his mouth pulled down into an exaggerated frown. If I didn't comply in the next few seconds, the crocodile tears would start and he'd cause a louder uproar than my singing.

"Okay, okay...!" I tilted my head away from his view, a pained look crossing my face. This had become a weekly habit of his and Todomatsu always knew how to get his way.

As I took in a breath to start singing a lullaby, my door slammed open and startled both of us as our oldest brother glared down at the youngest sextuplet. His hair was roughed up like he had been sleeping and the dark circles around his eyes told us that we had woken him up.