Oh man, this is a dynamic I'd love to see in the manga.
You two get along sooo well!Hey, that's not fair!!Oh, you sure?
Katou-saaan! Sasaki-san is violating meeeee!Why you!grabWhat the hell, Kuroki?!!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?HmmphHehe... I agree with you.Kuroki and me? You've gotta be kidding! Who would want such a perverted younger sister?!Hmph!Hah!You're like two sisters!*Elective PEHuh?Mm?You look pretty similar?Kuroki-san and Fuuka...HmmmI've been thinking this for a while now, y'know,
when you look like this