Munenori Agawa works tirelessly for the female-dominated company Lévres Cosmetics, where he takes a keen interest in his beautiful senior, workaholic Sayako Asou. Due to a series of mishaps, the pair seem to interact more often, much to Munenori's pleasure.

However, the appearance of a young girl strains their newfound relationship. Her name is Rena Amami, and despite having the appearance of a middle school student, she is actually 19-years-old. This is due to Progressive Rejuvenation Syndrome, a rare disease that causes to age regression of those it inflicts. The only way for Rena to reverse its effect is to regularly kiss Munenori, as he is one of the few people whose saliva contains the correct enzyme required for treatment.

Sakuranbo Syndrome - Cupid no Itazura II is a romantic drama that follows Munenori when he is placed at the center of a complicated moral dilemma, a situation where he must find a compromise between giving Rena her life-saving kisses and remaining faithful to the woman he loves.

Included one-shots: Volume 9: Nijidama Punch Volume 10: Psychic Duo Volume 11: Nijidama Bonbon