Inspector Totsugawa of the First Investigation Division goes to Tsuruoka in Yamagata to attend the wedding of the son of Inspector Mukai, his former colleague who now works for the Yamagata Prefectural Police. While sightseeing at Mt. Haguro after the ceremony, he notices a young woman drawing him in her sketchbook. She introduces herself as Yuka Shiraishi and says she came to draw the Dewa Sanzan. Signing the drawing of Totsugawa next to the five-story pagoda with her initial, a 'Y' in the corner, she gives it to him as a present. The next morning, the corpse of a young woman who has been stabbed is discovered in a forest in Tsuruoka. When Totsugawa, on his way back, hears that a sketchbook signed with a 'Y' was found at the scene, he follows Mukai there. However, the body is not Yuka, the woman Totsugawa had met, and while no items pointing to her identity are found, the sketchbook is the same one Yuka had the day before.