I can'T find you a link, since I'm at work, but Watase Yuu's "Sakuragari." It's her first foray into honest to god yaoi, but more than that, it has to be the single most fucked up thing by her I've ever read, and there is no magic, no curses, no people going missing, and nothing supernatural at all. It's just got a character who is completely fucked up in the head who gets obsessed with this nice, normal, naive, painfully honest kid (I say kid, but he's eighteen). It takes place during the Taisho era (between the Meiji and Showa), so around the 1920's, and...yeah, I can't think of anything to say but "it's fucked up." Because the bad guy, the fucked up one, is the super-pretty Watase-Yuu-brand long-haired hottie ala Hotohori, so you're not expecteding the MESSED UP IN THE HEAD, and messed up in a disturbingly human way--he's cold, he's callous, and then all of a sudden he's obsessed.

There's a scanlation of it, because, hell, it's Watase Yuu doing yaoi, so of course someone snapped it up to scanlate.