Depths of Winter (Season 2, Episode 10)

The Bottom of Winter is the tenth episode of the second season of the Mushishi anime series, Mushishi Zoku Shou.

Plot
Ginko finds himself unable to leave from a Mountain. He expects the spring season to come about in the mountain, however the mushi known as Oroshibue ( Winter Mountain wind whistle) are unable to leave the mountain. This is because a turtle like Mountain Lord has closed the mountain and is not allowing the mushi to migrate.

As a result of this, it is still winter in the mountain. Ginko tracks down the Mountain Lord and tries to persuade it to open up the Mountain and let the mushi migrate. However, the Mountain Lord makes the Oroshibue push Ginko in a pond. Ginko then realizes that he can breathe inside the pond, which is made of mud.

He also finds the other animals hibernating and healing themselves, because there is Kouki drops emanating from the bottom of the pond. When Ginko finally resurfaces, he realizes that his Backpack was left open and some Oroshibue are drinking his Kouki. Spring has also come about in the mountain. Ginko finally leaves the mountain and has a revelation: that the Mountain lord had planned to use Ginko's Kouki and heal the animals and mushi of the Mountain.