Serious Heroine: Betrayal, Pleasure, Training (2022)

Sinopsis

Maika Hirai is a shy and timid schoolgirl. One day, a string of kidnappings occurs in her neighborhood, and she learns that one of her few acquaintances is one of the victims. Determined to take action, she turns to her admired childhood friend, Rei Tachibana, a brilliant researcher. With Rei's help, Maika acquires the Cybergun "Cyan" and sets out to solve the case—unaware that the entire incident is part of Rei's wickedly calculated trap…