>>273774506He knows she was brainwashed but does not know to what extend, so at least being near her while she is still at school, just to make sure she wont cross a line she will clearly regret later, or get in trouble, would be a normal thing to do even if she was just his friend.
I will just remind you that
>>273767241 is pretty much the state he just left her last chapter, he has no idea how things went after they split up. MC basically went 'yeah my shizo ex girlfriend with brainwashing powers totally wont try to ruin life of my crush'. "WELL AT LEAST I KNOW I LIKE HER" my ass.