I'm Not Your Steppin' Stone (Yaoi Manga)

Sakai Kazuya is a 23 year-old man in love. Unfortunately, the object of his affection is a woman who's only interested in well-educated men. Sakai never finished high school-he's been living off his brawn, not his brains-so he enlists the aid of the woman's younger brother, Ezumi Masashi, to help him pass the high school entrance exam. Ezumi is happy to assist, but his services come with a very steep fee; he isn't interested in money-he has his sights set on Sakai's other assets...