I feel like Tatsumi-san might be autistic. He's got no common sense, he has difficulty understanding social cues, he tends to question social norms (why is ... like that), he's never been taught how to have a normal social relationship only being scolded when doing something 'wrong' and being labeled a troubled child because of it, he has a habit of collecting things and difficulty controlling his anger, as well as a difficulty reading other people's emotions.
Motomete Yamanai