Mission: Yozakura Family, Volume 1 (Mission: Yozakura Family #1-7)

Taiyo Asano is a super-shy high school student and the only person he can talk to is his childhood friend Mutsumi Yozakura. However, Mutsumi comes from a line of master spies with amazing powers. Her oldest brother, Kyoichiro, is obsessed with Mutsumi and out to kill anyone who gets remotely near her - and his next target is Taiyo! The only way for Taiyo to save himself from Kyoichiro's murderous clutches is to marry Mutsumi!