Nishino Ryuunosuke

The older brother of the protagonist. He only suffered light wounds during the tragic accident during their childhood, thus is healthy and fertile, unlike the protagonist.
A genius overbrimming with curiosity and very free-spirited. He left the family shrine to his younger brother and move to Tokyo to pursue the career of a novelist.
He has quite a bit of experience with women, but he is often refused due to his abnormally large penis size and high endurance.