Teenage assassins Mahiro and Chisato visit the coastal city of Miyazaki for a contract and a vacation, but they unexpectedly cross paths with a legendary, bloodthirsty assassin looking to add to his kill count.

Shinsuke Kujo is a chair craftsman who lures people into his apartment and murders them to use the body parts for constructing a chair. Kato, a representative of a chair company, finds his website on social media and suggests a meeting. She's quickly enamored with him both professionally and personally, unaware of his true nature as a serial killer.