In the autumn of their first year in high school, some incident spurred Tomomi and Kaoru to promise to be friends forever. However, at their present age of 41, the two of them have gone through different lives. Tomomi has built a happy family that everyone envies while Kaoru lives for her career as a movie producer. The differences in their lifestyles have created a distance between them. The two friends meet again for the first time at a class reunion after 20-something years and return to their former closeness. However, Tomomi has one suspicion. Kaoru knows too much about her own family. Is her husband and good friend having an affair? When Tomomi gets to the bottom of the matter, an inconceivable fate awaits her and Kaoru. The two of them are at the mercy of a harsh destiny, and before long, they learn what is hidden in each other's hearts.