11eyes: Tsumi to Batsu to Aganai no Shōjo

As the world around him inexplicably shifts into a crimson-hued nightmare, a seemingly ordinary high school student finds his mundane life shattered. Each night, the familiar city transforms into a desolate, monster-ridden landscape, forcing him and a handful of other bewildered teens into a desperate struggle for survival against grotesque creatures and an encroaching darkness. They are united by this terrifying shared experience, each grappling with the sudden, violent alteration of reality. Caught in a perilous cycle between their normal days and the brutal, blood-red nights, these young individuals must quickly learn to fight for their lives and uncover the truth behind their world's terrifying metamorphosis. As alliances form and mysteries deepen, they face not only external threats but also the unsettling question of what it means to exist when reality itself is under siege.

✦ AI-drafted summary