"Don't worry. I’m definitely a man." After inheriting a 1-billion-yen ring from her grandmother, Melissa hires a bodyguard to protect herself—but the one who shows up is a male maid! Dressed in a maid uniform over his muscular frame, Arthur flawlessly handles housework while effortlessly beating down anyone who dares go after the ring. At first, Melissa is bewildered by his eccentric behavior, but as they spend time together, her guarded heart slowly begins to open... Living under one roof with a dangerous maid, her life is about to get way too exciting!