Story
After the disastrous launch of an experimental 7G cellular network warps reality itself, Japan is left devastated with civilization collapsing and being reduced to scattered, isolated settlements. In addition, the 7G Incident has created strange phenomena and affected the surviving population in various ways, such as transforming the residents of Agano into intelligent animals once they reach the age of 21. Two years after the 7G Incident, young student and Agano resident Shizuru Chikura comes across evidence that her missing friend and classmate Yoka Nakatomi is actually alive and well in Ikebukuro. With the warped landscape too dangerous to travel on foot, Shizuru and her friends commandeer an abandoned Seibu 2000 passenger train with the intent to follow the Seibu Ikebukuro Line to Ikebukuro and reunite with Yoka.