Mei, whose full name is Mizuki Meiji, works at the Azuki-so care home and discovers a resident beaten to death. Although five elderly residents saw the culprit from the same room, they give five different colors for the clothing: red, blue, white, black, and green. With the weapon missing and testimony at odds, suspicion falls on someone important to Mei's colleague Haru, and mystery-loving Mei begins to investigate.

The five witnesses gave five conflicting colors for the culprit's clothing.

After her lawyer husband is murdered, a woman secretly suspects their adopted son, Shishi. Asked to investigate, former detective-agency employee Yuki Wakabayashi confronts the complicated family circumstances and darker secrets surrounding Shishi, whom he once tutored, and Shishi's friend Rito.

A mystery that moves from suspicion surrounding a murdered uncle and an adopted son into the darkness of a complicated family.