Hourglass of Summer

Makimura Koutarou is determined to confess his love to Serizawa Kaho during their summer vacation, but a chance encounter with a mysterious girl sends him hurtling into the future. There, he discovers that Kaho-chan has become his girlfriend, but has also tragically passed away. Returning to his own time, Koutarou sets out to alter the course of events and save his beloved, driven by his unwavering resolve to change their fate.