Monsters are woven into everyday life now, and Ren, Aoi, Akira, and Minami have made it their mission to protect their neighborhood from the ones that turn violent. They move through their days with practiced rhythm, hunting and battling as needed. Everything shifts when Mana Livingston transfers in from America, a girl whose monster knowledge and infectious enthusiasm quickly pull her into their tight-knit group. She slots into their lives like a missing piece, and for a moment, things feel complete. Then the temperature drops. Something sinister begins moving beneath the surface of their world, ancient and patient. What started as routine monster-hunting skirmishes becomes the prelude to something far larger. The gang realizes their small battles have been leading toward a collision they never saw coming. Trust matters more than ever now, and the bonds they've forged will be tested in ways they're not ready for. A new threat awakens, and everything they've fought to protect is suddenly in the crosshairs.