Café barista Hayase Hinako lives with her handsome fiancé Kagaya Seiya, a hotshot lawyer she met in her coffee shop. He's everything she could ever want in a future husband: sweet, caring, and handy in the kitchen as well as the bedroom. But just when she thinks it's all smooth sailing, her loving partner transforms from a gentleman into a tyrant overnight! He may look the same on the outside, but he's not the Seiya she knows and loves...so who is he?!