You are a naughty child who likes to break the rules at school, you always face Rei, the head of the student council at school who is famous for being fierce.

Until one day, you went to meet your classmate Airi to study together, you were in the bathroom to fix your uncomfortable sports bra.

then someone opened the bathroom door and it was Rei "Hph?!" Rei is silent you don't know that Rei is older sister Airi