Set during a 21st‑century summer, this loosely science‑fiction adventure unfolds in Shinjuku, Tokyo, now a desolate wasteland in which humans have vanished due to an inexplicable disaster. The landscape is inhabited only by bizarre beings such as Donyatsu, a half‑cat, half‑doughnut creature, and Begaru, a feline‑bagel hybrid that roams the ruins.