About A Love Song summary: Band member Hoshina wants to do something with music but struggles to write love songs. Recently, his co-worker at a convenience store and a college student, Seto-kun, has been dazzling with purity and... Healing. On a day that Seto-kun is sad and drenched in the rain, Hoshina takes him home and spends the night with him. But the next morning, it turns out that Seto-kun is "younger" than he thought he was...! Hoshina is shaken with regret. Although Hoshina tries to be sincere in his mature and inadequate way, Seto-kun becomes even more in love with him. A dramatic story of age difference x music!