Ginko encounters a young woman being followed by a mysterious, watery creature. The woman becomes weak, and her family believes it to be lovesickness. Ginko reveals the truth of the Mushi attached to her, but the woman must decide whether to give up her body to the Mushi, or to dispel it and continue living.
The girl is told that in order to protect herself from the Mushi, she must show it a mirror when it becomes visible. However, the hand mirror she possesses was given to her by a traveling mirror polisher who dumped her for being too much of a tomboy. Thus, she has bad feelings associated with it and refuses to clean it, leading to it being useless. Eventually, Ginko convinces her to clean the mirror. After a while, she sees the signal from her former lover. The girl runs off by herself to the meeting location, but realizes that the light was merely some glass in a birds nest. The Mushi appears at that moment, and she drops her mirror. However, when the Mushi tries to replace her, it is dispelled by its reflection in the girls eyes. Ginko takes the girl back home, where she recuperates. As Ginko is leaving, she falls in love with him, having to be held back by her parents. Ginko finds the Mushi in its original lake, and tells it that he can take it to a lake deeper in the mountains where no humans are.