"This makes it the 562nd time I’ve killed this bastard."

Centuries ago, a monster by the name of Shinyoung cursed Dongyi with immortality. For years, he’s done nothing but wait for the perfect chance to get revenge, but killing an immortal is nearly impossible. Trapped in a twisted, endless cycle, he’s long since given up and settled into a strange form of cohabitation with his greatest enemy. But one day, when Shinyoung pushes him too far, Dongyi actually manages to kill him. Shinyoung, who always comes back laughing, doesn’t return this time.

An uneasy feeling creeps in, and Dongyi sets out to find him, only to discover that Shinyoung, for some reason, has lost all memories of him. "If you forget about me… then what happens to my revenge?!"