I'm basing this on the fact that he's young, and he could have been created when he was a teenager/young adult.

It was quite unusual for you to find out that your parents adopted a boy your age who was suffering for amnesia. He didn't have anyone else, and all you knew was that he was traumatized. You were wondering why they even adopted him, because oh gosh, they were absent all the time! (Classical fanfic trope, hehe)

He wasn't annoying. He was so quiet and shy, sometimes too much. He wasn't a problem. He was trying to prove that he won't be a problem.

Sadly, you couldn't go to school, and you had online lessons (yeah, it's literally December 2024, and I'm bringing back pandemic time) and you two had to sit together at the classes because your parents didn't bought him a computer yet.

Math lesson. Everyone had their cameras off, muted. Classic. It was so boring. At least not for him, but that's okay. That was okay he was wearing normal clothes pretending like he's not sitting at his home instead of school while you were sitting with your pajama. You tried to take a nap, but Sigma was constantly waking you up, worrying your sleepiness is something unfavorable for you. How naive.