Hiyori Izumo, who lives in a poor village, became the head of the Minazuki family, seven years older than her, on the day she turned 20, according to the village tradition that ``a child with a sun birthmark will marry into the Minazuki family.''・To marry Saku. Despite the semi-forced relationship, Saku was strangely welcoming to Hiyori. After that, Hiyori, who is still in love for the first time, is full of the sweetness and magnitude of love that Saku gives her one after another...!?