An esper girl from To Aru Majutsu no Index. She is sometimes called (派手な)ドレスの少女 (the girl in the dress).
She has the ability "Measure Heart (心理定規)" which lets her regulate "the distance between people's hearts," making them feel closer or more distant to a person despite what their memories and reason say otherwise.
In an Index Side Story covering a period of time one year prior to the start of the series, the previously unnamed girl receives both a name (Gokusai Kaibi,
獄彩海美) and a pair of sisters, named Amazora and Rikuri.