Yuuto, who transferred from Tokyo to a rural high school, is spending a quiet school life, struggling to find a place where he can settle his mind in the unfamiliar environment. On a rainy day, he meets Saki, a girl with a mysterious aura. As a fellow transfer student, Saki is always bright and naturally blends in with people, and Yuuto slowly finds himself paying attention to her. Spending time together after school and growing closer, Yuuto suddenly realizes that Saki is not human. Caught in the act, Saki asks him to hide her identity, and Yuuto accepts the promise. Since that day, the two build short yet peaceful moments by taking pictures and sharing ordinary daily life together. However, a destiny is set where Saki cannot stay with Yuuto for long. A being who might disappear someday, and a person desperately holding onto those memories until the very end. Their encounter leaves a gradual, yet undeniable trace amidst their quiet daily lives.