A year has passed since Tooru Honda began living in the Souma residence, and she has since created stronger relationships with its inhabitants Shigure, Kyou, and Yuki. She has also grown closer to the rest of the Souma family and has become familiar with their ancestral secret, having helped them with many of their personal issues. The closer Tooru gets, however, the more she begins to realize that their secret holds a darker truth than she first presumed. Summer is approaching and Tooru is invited to spend her days with the Soumas, mainly Kyou and Yuki. Tooru wishes for an easy-going vacation, but her close relationships with the two boys and the rest of the Soumas may prove to cause trouble. As they grow more intimate, their carefree time together is hindered by older hardships and feelings from the past that begin to resurface. The Eternal Banquet also dawns on the members of the zodiac, and they must tend to their duties alongside the unnerving head of the family, Akito Souma. With the banquet approaching and a plethora of feelings to be solved, will Tooru's life with the Soumas remain peaceful, or will she find herself in a situation from which she cannot escape?

Tooru Honda has always been fascinated by the story of the Chinese zodiac that her beloved mother told her as a child. However, a sudden family tragedy changes her life, and subsequent circumstances leave her all alone. Tooru is now forced to live in a tent, but little does she know that her temporary home resides on the private property of the esteemed Souma family. Stumbling upon their home one day, she encounters Shigure, an older Souma cousin, and Yuki, the prince of her school. Tooru explains that she lives nearby, but the Soumas eventually discover her well-kept secret of being homeless when they see her walking back to her tent one night. Things start to look up for Tooru as they kindly offer to take her in after hearing about her situation. But soon after, she is caught up in a fight between Yuki and his hot-tempered cousin, Kyou. While trying to stop them, she learns that the Souma family has a well-kept secret of their own: whenever they are hugged by a member of the opposite sex, they transform into the animals of the Chinese zodiac. With this new revelation, Tooru will find that living with the Soumas is an unexpected adventure filled with laughter and romance.

Despite Kyouko Honda's tragic death, her vivid memory lives on, providing guidance through times of hardship to her close ones. However, Kyouko was not always the wise and radiant person that she is fondly remembered as in the present day. Feeling deserted by her own family and rejected by society, a young Kyouko abandons stability for a life of delinquency, jeopardizing her education and future. Fortunately, her descent into despair is interrupted by a fateful encounter with her husband-to-be Katsuya, who has recently started his teaching internship at her school. With a composure surprisingly unaffected by Kyouko's tantrums, Katsuya quickly wins her over through his gentleness and attention toward her—sincere gestures that she has never received before. As the two grow closer together, Kyouko opens her tormented heart to him and, along with it, a door to new horizons.

Every day, a young girl wearing a mask stands by the beach and sings a nostalgic melody. After experiencing two sudden heart-wrenching partings when she was only a child, Nino Arisugawa has been singing her songs to the ocean, bound by a promise made with her two childhood friends—her first love, Momo Sakaki, and a boy who composed music, Kanade Yuzu Yuzuriha. Having never met each other, the boys both individually promised that if Nino was ever separated from them, her voice would be the beacon to reunite them once again. After six long years, destiny has finally placed Nino, Momo, and Yuzu in the same high school. However, the passage of time has changed many things in their lives—while Nino relentlessly attempts to fulfill her childhood promise with the boys, Yuzu's feelings for her from the past resurface, and Momo goes to great lengths to prevent a reunion with Nino. Through music, will they be able to mend their friendship and overcome all the feelings involved in this complicated love triangle?