BLUE WARS by nakamura yoshiki
as translated from the flap: "sera ryousuke, son of a budou family and has a "super muscle body". but the truth is, he's a guy whose hobbies are gardening, knitting, cooking, and sewing and loves flowers!? and the person (kanji: guy) ryousuke likes is his fighting buddy, nidou gunma *heart*. one day, in front of ryousuke, who eagerly wishes to become a woman, a miraculous flower spirit appeared, saying "i'll make you a girl"...!!"