Yatteraneeze!

Hiroya is an A-student who's sick of being the unnoticed "quiet one" at his school. He enlists the aid of a "cool" student in his class, Takashi, to help him remake his image. Takashi tells him to bleach his hair, get an earring and a new wardrobe, and oh yeah, have sex with me. The story follows the development of their relationship, as well as that of Takashi's older brother and his lover (the latter of whom is a slut; he's been screwing Takashi and makes a try at Hiroya, too). Things get very serious and realistic at certain points, but their relationship gradually moves from mutual exploitation through friendship to genuine love. - reviewed by Nora

A few extra characteristics:

1) Sort-of UST. They do handjobs and petting for like five books before actual intercourse happens.

2) Sophistication vs. innocence is a major theme: Hiroya's completely clueless about everything from sex to cigarettes, while Takashi's very much a man of the world.

3) AIDS is a subplot, when Takashi's brother's slutty boyfriend turns up HIV positive and Takashi worries that he might be, too. - reviewed by Nora