Watanuki notices a pair of wings started to grow from the back of a classmate. When he brings home a feather Yūko warns him not to become bait. As the wings on the girl’s back grow bigger, her personality changes and she becomes unkind. Eventually she attacks Watanuki, but Dōmeki and the pipe fox intervene, and the pipe fox destroys the wings parasite that was controlling her. Yūko explains that the parasite will only inhabit certain susceptible people.