Kokushi

is a villager who joined Boro's cult.

Kawaki Arc
When a disease plagued his village, Kokushi tended to his son Kanchi, who had fallen ill. Suddenly, Boro and his cult arrived to his village, claiming to be there to save them. Kokushi himself had been infected by the disease and distrusted outsiders. To prove themselves, Boro "healed" him, his son, and the other villagers. To escape poverty, Boro convinced Kokushi and the other villagers to join his cult in order to relive the experience of the Infinite Tsukuyomi from a decade ago.