The Narita family is given the deep freeze when one of Mrs. Tachibana's spies glimpses our hapless heroine, Hatsumi, with her treacherous ex-"boyfriend," Azusa. Thinking they're being ostracized because she's turned down her former "master" Ryoki's advances, Hatsumi tracks Ryoki down and begs him to take her back...as his slave! But this only pisses lovesick Ryoki off, who actually wants Hatsumi to like him. He has another plan to win Hatsumi's good graces: he wants her brother, Shinogu, to be his private math tutor, and he wants his lessons to take place at the Narita's apartment! Shinogu doesn't like it...especially since Hatsumi is starting to fall for Ryoki!