Cotton Changeling (Episode 21)

Cotton Changeling is the twenty-first episode of the anime series.

Synopsis
A couple summons Ginko to investigate their sick child, Watahiko, who has developed green spots all over his body.

Plot
A family calls Ginko to investigate their sick eldest son, Watahiko, who has developed green spots all over his body. The mother, Aki, explains that when she was pregnant she traveled in a forest and noticed a green spot appearing on her clothes and seeing her son Watahiko, she got reminded of that green spot. Ginko asks if the child was looking like a human when it was born and the father explains that a strange green mass was born and it managed to escape the house by going under it. A year later, he heard some noise from under the house and found a child. Aki said it was their child and seeing the resembles the man accepted it. The child Watahiko, grew fast, although it couldn't talk or feed by himself. A year and half later, another child appeared and then another. Ginko explains its a Mushi Watahaki, that enters pregnant women and takes place of their child. One year after birth, it sends a hitotake in the shape of a bady to the parents, which has invisible strings connected to the main body and serve his as nourishment. Ginko tells them that Watahiko will soon serve its purpose and die and when he do, he will cough up a lot of seeds and they need to kill him before that happens. The family initially refuse, but Ginko explains the Mushi killed their child and these children aren't theirs. The man agrees and Ginko uses poison and then burns Watahiko's body. Ginko agrees to let them keep raising the other children, but tells them if something happens to call him.

Less than three months pass and Ginko receives a letter and returns to the house. The man explains that the children started to grew and develop faster. There was things he though only one child, but others younger started to do it too and they even started to speak. As the second son is also showing the symptoms and asking the father to not kill him, the man couldn't do it. When Ginko enters the house, the children had convinced Aki to save them and she attacks and stabs Ginko.

Ginko stays for a couple of days until he recovers and then goes to the second son. The child wonders why he will kill him and he explains its because they feed on children and he can't allow that to continue. Having no choice and wanting to protect its seeds, the Watahaki makes the other children burn the house and along with all the children. Ginko then checks the burned house and gives an "egg" to the couple saying that when Watahaki meets a crisis it cuts the roots to hitotake and tries to save the seeds. The hitotake then change form and enter hibernation, but he doesn't know when they will wake up as it could be even after the parents death.

Leaving the place, Watahaki asks Ginko what he gave them and he explains its a mineral from his provisions. Ginko takes out a bottle that contains the Watahaki and wonders why it isn't hibernating, but Watahaki comments it isn't tired. Watahaki wonders why Ginko isn't using this chance to kill it, and Ginko tells it that the end of its life hasn't come yet, making Watahaki comment that Ginko is a mysterious creature.