Yuriko Yamaguchi is a Japanese voice actress and narrator. She was previously affiliated with Vi-Vo and is currently affiliated with Aoni Production. Her major roles include, Nico Robin in One Piece, Ritsuko Akagi in Neon Genesis Evangelion Sonia in Eureka Seven and Nurse Joy in Pokémon.

Dr. Ritsuko Akagi is a fictional character from the Neon Genesis Evangelion franchise, created by Gainax. She is the head of the first section of the technology department at Nerv headquarters, and one of the main developers of Evangelion units. In 2005 during college, Ritsuko met Misato Katsuragi, who became her best friend, and befriended her boyfriend Kaji, whom Ritsuko considered annoying. In 2008, after completing her studies at Tokyo-2, Ritsuko joined Gehirn Research Center as the head of Project E. Following her transfer to the special agency Nerv, Ritsuko became responsible for the management of the Magi supercomputer. At Nerv, Ritsuko comes into close contact with her mother's lover Gendo Ikari, learning secret information that is withheld from almost all other members of the organization.