After the accident in which she lost her mother, 16-year-old Tooru moves in with her grandfather, but due to his home being renovated, is unable to continue living with him. Claiming she will find someone to stay with but also fearing the criticism of her family and not wanting to burden any of her friends, Tooru resorts to secretly living on her own in a tent in the woods. One night on her way back from work, she finds her tent buried underneath a landslide. Yuki Souma, the prince of her school, and his cousin Shigure Souma, a famous author, stumble across Tooru's situation and invite her to stay with them until her grandfather's home renovations are complete. Upon arriving at the Souma house, Tooru discovers their secret: if a Souma is hugged by someone of the opposite gender, they temporarily transform into one of the animals of the zodiac! However, this strange phenomenon is no laughing matter; rather, it is a terrible curse that holds a dark history. As she continues her journey, meeting more members of the zodiac family, will Tooru's kindhearted yet resilient nature be enough to prepare her for what lies behind the Souma household's doors?

Having reached professional status in middle school, Rei Kiriyama is one of the few elite in the world of shogi. Due to this, he faces an enormous amount of pressure, both from the shogi community and his adoptive family. Seeking independence from his tense home life, he moves into an apartment in Tokyo. As a 17-year-old living on his own, Rei tends to take poor care of himself, and his reclusive personality ostracizes him from his peers in school and at the shogi hall. However, not long after his arrival in Tokyo, Rei meets Akari, Hinata, and Momo Kawamoto, a trio of sisters living with their grandfather who owns a traditional wagashi shop. Akari, the oldest of the three girls, is determined to combat Rei's loneliness and poorly sustained lifestyle with motherly hospitality. The Kawamoto sisters, coping with past tragedies, also share with Rei a unique familial bond that he has lacked for most of his life. As he struggles to maintain himself physically and mentally through his shogi career, Rei must learn how to interact with others and understand his own complex emotions.

As Tooru continues on her quest to become the greatest maid and Kanna Kamui fully immerses in her life as an elementary school student, there is not a dull day in the Kobayashi household with mischief being a daily staple. On one such day, however, a massive landslide is spotted on the hill where Kobayashi and Tooru first met—a clear display of a dragon's might. When none of the dragons they know claim responsibility, the perpetrator herself descends from the skies: Ilulu, the radical Chaos Dragon with monstrous power rivaling that of Tooru. Sickened by Tooru's involvement with humans, Ilulu resorts to the typical dragon method of resolving conflict—a battle to the death. Despite such behavior, she becomes intrigued by Kobayashi's ability to befriend dragons and decides instead to observe just what makes Kobayashi so special. With a new troublesome dragon in town, Kobayashi's eccentric life with a dragon maid is only getting merrier.

During the summer of her freshman year of high school, Yuzu Aihara's mother remarried, forcing her to transfer to a new school. To a fashionable socialite like Yuzu, this inconvenient event is just another opportunity to make new friends, fall in love, and finally experience a first kiss. Unfortunately, Yuzu's dreams and style do not conform with her new ultrastrict, all-girls school, filled with obedient shut-ins and overachieving grade-skippers. Her gaudy appearance manages to grab the attention of Mei Aihara, the beautiful and imposing student council president, who immediately proceeds to sensually caress Yuzu's body in an effort to confiscate her cellphone. Thoroughly exhausted from her first day, Yuzu arrives home and discovers a shocking truth—Mei is actually her new step-sister! Though Yuzu initially tries to be friendly with her, Mei's cold shoulder routine forces Yuzu to begin teasing her. But before Yuzu can finish her sentence, Mei forces her to the ground and kisses her, with Yuzu desperately trying to break free. Once done, Mei storms out of the room, leaving Yuzu to ponder the true nature of her first kiss, and the secrets behind the tortured expression in the eyes of her new sister.