Hajime, a postman, wakes up with amnesia after Valentine's Day. Reika has clues about his lost memories from that day. He tries to solve the mystery of his forgotten Valentine's Day events while their paths cross.

Achu is a postal worker, known as the "disappointing handsome guy". Achu, who is one second faster than others, always wakes up one second before the alarm clock rings. Rinka is a seventh year photographer in college. Rinka, who was one second slower than others, always closed her eyes when taking photos and never opened them to take a commemorative photo.