Hiro Nimura acts as the founding director of the Psychic Power Research Society at Yamashiro Academy. He publicly presents himself as a genuine psychic, demonstrating feats like card identification, psychically "killing" and reviving a heckler, inducing paralysis, and levitating objects. These abilities are later exposed as stage magician tricks. Mai Ishiki publicly denounces his demonstrations as fraudulent, destroying his credibility.

After this discrediting, the society's sub-director, Rika Matoba, uses her psychic powers to hypnotize the club members. She removes Hiro from his position and installs Yu Hokuto as the new director, altering the members' memories to believe Yu had always held the role. Hiro then approaches protagonists Yumi Sado, Keiko "Okei" Okura, and Mai Ishiki. He portrays himself as an ally opposed to Rika's manipulation, warns them about the society's dangers, and helps them infiltrate its fortified headquarters to rescue the captured Okei.

During the rescue mission, Hiro provides the girls with tracker bracelets, ostensibly to help them navigate the headquarters and locate each other. These bracelets are later revealed to be anti-esper suppression devices that neutralize their psychic abilities. This betrayal exposes Hiro's true allegiance; his earlier opposition to Rika was an elaborate ruse to capture all three girls. He intends to perform psychic lobotomies on them as part of the Academy Domination Project, a scheme aligned with the EDF (ESPER Domination Force) to control the academy through esper supremacy.

Hiro's plan is thwarted when Mai Ishiki's super-strength, fueled by anger, breaks her restraints. The confrontation destroys the Psychic Power Research Society. Hiro and Rika subsequently disappear from the academy, their ultimate fates unresolved.