The Light of the Eyelid is the second episode of the anime series.
Sui is the youngest daughter of a head family, about six months ago, she contracts a disease which makes her eyes sensitive to light, but no doctor can help her. She was given to one of the serving family to look after her and is kept in a storage shed in complete darkness. Biki comes to visit her and Sui decides to reveal the truth about her disease. She explains that she has a Mushi in her eyes and that she learned to close her second eyelid and see the complete darkness. There she sees a river of light, a river consisting of small Mushi, but every time she gets closer to it, a man with one eye tells her to not go.
Biki stays with her each day and plays in the darkness of the shed. His mother is afraid he may get infected by her disease and her fear turns real when Biki suffers from light sensitivity in the morning. She visits Sui, giving her food and tells her that Biki won't be coming anymore as he also got her disease. Hearing the news, Sui crying for Biki and goes into the river of light. The mother returns to Biki and finds Ginko, who had performed treatment on Biki and had given him medicine which will heal Biki. When Biki wakes up healed, Ginko explains that his Manako Yami Mushi was newborn and that it multiplies in darkness. Ginko explains that healing Sui will be harder, as she was kept in darkness for longer and will go to her during the night.
Visiting Sui, Ginko realizes she went into the river of light and had permanently lost her eyeballs. He takes her outside and tells her to open her eyes while keeping her second eyelids closed. As she does, the Mushi inside of her is lured out from the moonlight. As liquid pours out, Ginko sees the Mushi coming out and tells her to close her eyes, which makes the liquid return to her eyes, but Ginko catches the centipede-like Mushi. He explains her eyeballs are gone and take out his fake glass eye and injects it with the liquid Mushi. He then places it into the left eyesocket of Sui, causing a pillar of light, but allowing Sui to see with that eye. Biki and Sui continue their lives normally, while Ginko heads out towards another Mushi case.