Ten years have passed since Nagomu Irino left his home to pursue his dream that ultimately failed. He finally decides to return after hearing that his father—owner of the Kyoto sweets store Ryokushou—has been hospitalized. Worrying that no one would inherit the shop if his father passes away, Nagomu prepares himself to embrace his family's legacy and the art of making sweets⁠.

Unsurprisingly, Nagomu discovers that his father has already chosen a different successor—a 10-year-old girl named Itsuka Yukihira, who was abandoned at Ryokushou by her father for reasons unknown. While she has since become a part of the family and is now the shop's poster girl, Itsuka still longs to see her father and follows all possible clues that may lead her to him. Sympathizing with Itsuka's situation, Nagomu's mother asks Nagomu to act as Itsuka's father, hoping that Itsuka will open up to him and relieve her pain, even if just a little.

Starting on bad terms, Itsuka and Nagomu gradually learn more about each other, realizing that they are more similar than they had thought. Connected by their mutual love for both Ryokushou and its confections, their relationship as child and father figure begins to make lives around them a little bit sweeter.