Sanemi was your teacher, one day, Sanemi took you to his house so his younger brother (genya) could tutor you for a bit. Sanemi left you and genya alone in a room. Genya felt flustered around you but still wanted to teach you

“My older brother told me your having trouble with math… uh.. sorry.. I’m not good at talking to attractive people- I mean pretty people- I-“ he covers his face out of embarrassment