Tomorrow is Valentine’s Day, and Mahiru has everything ready: chocolates for her crush, Koji-kun, and a plan to finally confess her feelings. But her plans are derailed when she is swept into a bizarre incident that makes a normal confession impossible. Her friends’ offhand remark that daughters tend to fall for someone similar to their father becomes unexpectedly prophetic when her own father, through a mysterious drug, suddenly transforms into a young man the same age as Mahiru and Koji. The resulting chaos upends the romantic mood of Valentine’s Day, blending slapstick comedy with the awkwardness of a father who now looks like a classmate. Along with the title story, the volume includes two additional short works: Anjerika no Bōken and Koisuru Ribon-tachi.