Keiko Okura

O-Kei is one of the protagonists in The Gakuen Choujo-tai. She falls in love with Nimura Hiro, one of the villains in the OVA, and she is energetic. Alongside Mai and Yumi, she utilizes her ESPER powers to protect Yamashiro High School. Her powers involve using her voice to amplify sounds to extremely high levels, creating wide-ranging, non-specific sonic explosions.