Curse? Yes. Spring of drowned Ashura (that three-headed goddess statue thingie...).
First Appearance: Manga Volume 34
History: Rouge is a girl from India whom Akane found, naked in a fountain, of all places. Soon after a guest in the Tendou Dojo, Rouge's curse is discovered when Happousai comes back from a routine panty raid, where he gets Rouge wet. Her normally docile and submissive demeanor changes to savage, rude and hostile when
her curse is activated. (Pansuto Taro is also involved in this whole
freaky story - I'll just say that Rouge has him accused of stealing from
her, that snake! ^_~)