I didnt understand one thing, if he is rank 7th is that means sumire is 6th? I can understand that being the first rank one time doesnt mean u will be rank first in overall too but him being 7th doesnt make sense. Maybe they didnt put sumire in sevens its the only option but confusing thing is they went there together as if they both in the sevens now. Also his sister is like a tsuntsuntsun-dere probably? She calls him failure but says good things about his strength.
