Fujiko Amacha is a 17-year-old girl from Ibaraki who once aspired to become both a doctor and an astronaut. Before being placed in cryonic preservation, she served as an overseas medical volunteer. She later emerges as a member of the Spring Team, which awakens a few months after Summer Team B near an island off the Kantō coast. The team travels to Ogino Fuji in Kanagawa Prefecture.

Fujiko has a strong and energetic personality, which helps her form a close bond with Hana Sugurono, another Spring Team member. Despite her resilience, Fujiko goes missing at a certain point due to a series of difficult events.

Her name includes a kigo, or seasonal word, for spring: "fuji" meaning wisteria and "amacha" referring to a type of hydrangea, both symbols of the spring season.