Shinyuutte Soko Made Shinakucha Ikenai No?

Takahashi Kento and Tanaka Issei have been friends since elementary school. When Issei learns that he has a disease that will cause his penis to shrink, he asks Kento to help slow the progression of the disease by massaging his prostate. At first, Kento is opposed to the idea, but after realizing that this is the only way to help his friend, he agrees.