A fork of Rural Dictionary
Yandere is an anime/manga slang for a character who is caring and loving at first, but who gets more psychotic and delusional in the end. Yandere character also usually shows obsessive and brutal traits. Yandere is a compination of words yanderu (to be sick) and derere (exhausted or love sick). Yandere is somewhat similar to terms tsundere and kuudere as these all describe characters attitude and how the character matures during the show.
School Days and Doki Doki Literature Club. You don't need any more accurate representation on what is yandere...