From Chibi Manga:

Yuu is a plain girl who had a determination to change when entering high school. Falling in love with the hot guy nicknamed as "White Prince", but somehow she's keeping an eye on the super sadist guy nicknamed as "Black Devil" too?!

She has a new neighbor who's so handsome! ...but he's also devilish.
and the worst part is that he's also her homeroom teacher!!

Featured as the in-game comic series in the mobile game Tokyo 7th Sisters, Let's Go! Nanastar Coms details the musings of all the 777☆SISTERS girls (pronounced "three seven sisters") in Nanastar!