That's When Things Changed (1993)

Moriyama leads and guides an organization that aims to create a global environment that can coexist with forest slime molds. During an activity in the park, other members spot members Nagayama and Itagaki making love to each other. Kijima could not forgive the fact that there was such a relationship in the same group, but when Moriyama learned of this, he told Nagayama that sodomy and living in search of slime mold were the same, and told Nagayama that he had a relationship with other members. He suggested that they have a relationship. Later, the body of Kijima, an opposition figure, was found...