After completing their training within an assassin organization, four young individuals are brought to a place called Azusa Manor for their final test. The test is simple and brutal: they must kill each other, and within six months only one survivor will remain. The four are strangers to the ordinary world, having spent their lives in the organization. Expecting a grim battle, they instead find themselves enjoying a six‑month reprieve, free to explore everyday life for the first time. They move into the manor, cook together, make friends, and savor the small pleasures of a normal existence. But the test is still running. Beneath the surface of their newfound camaraderie lies the ticking clock of a life‑or‑death contest, and the threat of violence never truly disappears.

As the story unfolds, the four assassins’ pasts come to light, along with the shadowy forces that orchestrated the test. Hidden conspiracies, the true nature of their training, and the identity of the mastermind behind the deadly game are gradually revealed. The manga balances offbeat comedy with the tension of a survival thriller, following the characters as they navigate both the absurdities of civilian life and the looming necessity of betrayal. In the final volume, the tangled threads of their shared history and the conspiracy converge, leading to a decisive confrontation that forces each of them to choose between trust and survival.