It's like tsundere from what I can tell but sort of, how do I say it, loving but goes psycho... like Kaede from Shuffle.[/QUOTE]
Yandere? Well, it's a derivative of tsundere (kinda), by combining 病んでる (yanderu, being sick) with デレ(dere). It refers specifically to heroines who's in love with the main character, but becomes mentally sick or unstable due to certain developments in the story, resulting in a "psycho lover" kind of character (Kaede from Shuffle is the classic example).
However, as far as I know, this word is not very widely used (I don't even recognize it myself). More commonly, the "psycho" version of the heroine is referred to as "Black/Dark (character name)" (ex. Dark Kaede), while the process is called 黒化 (kokka, blackening/darkening).
Last edited by kj1980; 2007-06-07 at 10:36.