Also known as: 獄彩海美, 心理定規
A character introduced in Toaru Majutsu No Index, and featured in the sidestory Toaru Majutsu no Index SS: Biohacker Arc.
For a long time only known as the Girl in the Dress (ドレスの少女) or Measure Heart, she is a teenage girl who participates in compensated dating for money. She is an operative of SCHOOL, acquainted with the ways of the Dark Side of Academy City, and the second of the three Gokusai sisters.
She has medium length blonde Wavy Hair styled in a Ponytail and Brown Eyes. She usually wears a pink or red sleeveless frilled Dress, leaving her shoulders bare along with Necklaces and Bracelets and White Sandals. She often has an Expressionless disposition.
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.