From Loveless' Site:
Narushima (blondie) is a really idle, bored and restless guy, and he is looking for something that will cure his state of boredom. For that same reason, he goes around picking fights, harassing girls, smoking & being a pretty awful delinquent in general (sadist!).Thoughts of finding that drug come to Narushima's mind.
After catching glimpse of Natsume (black hair), a male prostitute (who is said to be a bad influence by Narushima's senpai- Heitarou) may just be the drug he was looking for.
Note: not for the faint hearted (includes: bondage/rape/incest)