Shoko Aida shares classes with the Hyper Dolls, Mew Fumizuki and Mica Minazuki, and knows their acquaintance Hideo Akai. Driven by persistent curiosity, she actively investigates the Hyper Dolls, determined to uncover their secret identities. Her suspicions about Mew and Mica frequently become the topic of conversations with Akai, who consistently attempts to dissuade her inquiries, aiming to shield her from the dangers linked to their secret.

Shoko harbors unreciprocated romantic feelings for Akai. When feeling neglected or emotionally hurt by Akai's perceived indifference, she often seeks solace in alcohol, leading to intoxication.

Functioning as an investigative figure within the narrative, Shoko's persistent attempts to expose the Hyper Dolls' identities create minor complications for the main characters, adding tension to their efforts to maintain secrecy.