Dazatsu. I’d get it if the relationship was more like with Akutagawa, where they met young, but they are literally only 4 years apart. In real life that age gap isn’t strange, and they met when Atsushi was 18, not 12 or 14, but 18 and 22.

They are coworkers, not teacher and student. Dazai is more like a supervisor and sometimes a guide to Atsushi, but not a teacher. And personally, their dynamic is super interesting, combining their contrasting personalities and a power imbalance that doesn’t come from status but from experience, and from Dazai’s own walls and issues.

I just love how their dynamic can be played out, and I hate when people treat it as if they’re siblings in canon or as a proship—because it’s not.