Munenori Agawa finds himself deeply involved in the day-to-day affairs of the female-dominated Lévres Cosmetics, particularly drawn to the hardworking and attractive Sayako Asou, his senior. As fate would have it, a series of accidents leads to more frequent interactions between them, much to Munenori's delight. However, their budding connection faces a hurdle with the arrival of Rena Amami, a young girl who appears like a middle school student but is actually 19 due to a rare ailment known as Progressive Rejuvenation Syndrome. To halt the illness's effects, Rena must receive regular kisses from Munenori, as his saliva contains the vital enzyme for treatment. In 'Sakuranbo Syndrome - Cupid no Itazura II,' Munenori grapples with a complex moral dilemma, torn between saving Rena's life through his kisses and staying loyal to his beloved Sayako.