Sogou Mami

Sogou Mami (十河麻実) is a background character appearing in the Toaru Kagaku no Railgun manga. She has long black hair and is enrolled in Suzuyama High School as a third year. Her power is Hydro Hand, though her level is unknown, though likely around level 3 or 4.

She is briefly seen in a list of people provided by the Bank to Shirai Kuroko of a list of espers that can control liquid metal remotely, during the search for the esper that attacked Uiharu Kazari and Misaka Misuzu. This implies that she has some form of control over liquid metal.