Kind of crazy to me that there isnt more conversation regarding Zanka and self harm.
I know people usually see the term and have a very specific concept of it, and while Zanka doesnt exhibit it like that, he very much does exhibit it in other ways!!!!
When he gets angry and feels like a failure or feels weak, he actively punishes himself for it. Im still stuck on him biting his lip hard enough to make it bleed and almost immediately slamming his head into the concrete wall in front of him. On my first watch I shrugged it off as typical anime exaggeration but upon rewatching, they wouldnt have made him bleed in that case. Zanka was punishing himself for losing, for not being good enough to keep his place as top student.
And the well thing???? Hello??? Straight up starving himself.
Aside from overexerting himself in fights (which is kind of brushed over since everyone fucking does it), I havent seen too much of it with the cleaners but it was definitely a consistent habit beforehand.