Tooru Honda is a 16-year-old orphaned girl who gets invited to live in the house of her classmate, the handsome boy Yuki Souma, and his cousins, 16-year-old Kyou and 27-year-old Shigure. However, these young men and parts of the rest of their family (both close and distant) hold a curse; if they are hugged by the opposite gender, they transform into animals of the Chinese zodiac. Everyday is an adventure for sweet Tooru, as she gets to know everyone in the large family better (especially Yuki and Kyou), in both common and bizarre situations. But, the Souma family curse is certainly no laughing matter... It also holds horrible cruelty and heartbreak.