Secret Unrequited Love

ぼくの初恋をキミに捧ぐ

Mayu and Takuma have loved each other since age eight, when they met as the daughter of his doctor and the patient with a heart condition. One night Mayu overhears that Takuma is unlikely to live past twenty, a fact he doesn't yet know himself. The two go searching for a four-leaf clover, and Takuma makes the impossible promise to marry her when they both turn twenty.