Rin's physical appereance is quite similiar to his sons. The only difference is that Rin has a beard. He wears a black hat, round glasses, green jacket and blue trousers.
He first apperead in Episode 8, when he went to the match where his sons were playing. He taked notes about the game and after the Predators had won against Tsubakimori SC, he talked to Masaru about how his sons were playing, espesially about Ryuuji's own goals.