壬生 心乃助

"Don't call out to me so casually! The only one who can use that name is my big brother!"

1st year high school student.
Star Sign: Saggitarius
Soutarou's younger brother.

An underclassman at Lapis's school.
His older brother calls him 'Koko', but if anybody else calls him that he gets ragingly angry.
A real brocon, he's always making sure Soutarou doesn't have any undesirable girlfriends.
He has a cute face, but he talks rough.