Sakura Kurusu, daughter of the wealthy Kurusu family, has been in love with Haruto Nanase ever since Haruto became her servant 15 years ago. Sakura has asked Haruto to marry her every day for the past four years and each time, Haruto manages to deflect her proposal... One day, however, Sakura overhears Haruto tell another servant he only thinks of her like a little sister. Heartbroken, Sakura decides to change her strategy by going to Haruto's bedroom late at night in nothing but a revealing gown. She begs him to see her as more than a little sister. What will come of Sakura's devotion to her one true love...!? Follow a prominent daughter and her older servant in this heart―throbbing love game.