I've been thinking this for a while now, y'know, when you look like this

Kuroki-san and Fuuka...

*Elective PE

Hah!

Kuroki and me? You've gotta be kidding! Who would want such a perverted younger sister?!

Hehe... I agree with you.

Really, it would be such a pain to look after an older sister who talks about her friends' breasts and pubes in front of everyone, right?

Oh, you sure? Katou-saaan! Sasaki-san is violating meeeee!

You two get along sooo well!