Osamu has lived with his family for eleven years now—after his adoptive father, Mori Ougai fished him up at the young age of four years old. The moment Mori saw the young mer, it was like something clicked in his brain that said, "Yep, this kid is mine now!", because the next thing the young one knew, he was being taken to Mori's home and integrated into the mer domestication program. Growing up with a human family, there's of course been struggles, but Osamu has never once felt like he wasn't part of the family!
...Or at least, that's what Mori thought.
And why wouldn't he think that? Osamu has always been part of the family. He loves his siblings, his siblings love him. He loves his baba and papa, and his papa—and especially his baba, Mori—adores him. There was just... one thing that Mori had never even considered.
So yes, Osamu has been with the family for eleven years now. Being fifteen, he had really started to notice things. Like the fact that his brother and sister, Ranpo and Akiko, has Mori's hair. Or how his oldest brother, Sakunosuke, has their papa Fukuzawa's hair. How all of his siblings looked like his parents. And then there was Osamu, with brown hair nobody else in the family had, and red eyes that nobody else in the family had. Clearly adopted. Like, embarrassingly obvious.
He remembers when he was eleven and his little sister, Elise was born. Watching Mori naturally gravitate all of his attention to her. Sure, it was because she was a baby, and he wasn't, but... it was like realizing a special bond he could never have with his baba. How it felt, knowing he would never share any traits with his parents.
How other he was.
Which leads to now.
Okay, sure, maybe he was going through a mental health crisis, but this was clearly the only logical next step! Recruiting his childhood bestfriend (and secret boyfriend), Chuuya, to sneak off to the store after school with him. Then finding themselves in Chuuya's home across the street from his own, hidden in Chuuya's bathroom as the two teens figure out how to safely dye Osamu's hair. Black—that was the color Osamu had chosen. Mori's hair color.
The thought process? If we have the same hair, then I'll look just like Baba! So, with Chuuya's help, they managed to dye his hair. Osamu remembers looking at himself in the mirror happily after the fact, and blurting out if Chuuya thought he looked like Mori now. And then the crashing words—Chuuya, having not known the reason for Osamu's sudden want to dye his hair, just raised an eyebrow, and:
"...Well, no? I mean, you two don't look alike at all. Like, totally different faces and everything."
Mori didn't really bat an eye when Osamu came home late from Chuuya's house—it was normal for the two to hangout after school, afterall. He didn't question the beanie on Osamu's head either—it was kind of could out today. He just shrugged it off and continued making dinner as the fifteen year old ran up to his room... well, that is until he called everyone down for dinner and Osamu didn't come down.
Must not have heard me, Mori thought casually as he ascended the stairs to get his son down for dinner. He knocked on the door, "Baby? It's time for dinner." No response. Mori raises an eyebrow and knocks again, "Osamu. Dinner's ready, honey." No response.
Mori huffs, If that kid has his headphones blasting– He opens the door and pauses dead in his tracks, just... blinking at the sight before him. There, sat on the ground and staring at himself in the mirror with a deep frown was Osamu.... with black hair instead of the beautiful brunette Mori loved.
He was speechless, frozen in the door.
"Ah-" he starts, but stops, mouth opening and closing like a fish. Slowly, he steps into the room and closes the door behind him, and after a long moment of baffled, how do I even go about addressing this?? silence, Mori just blurts out,
"When did you dye you hair?? Why- how???"