Koichi Haruyama

Originally an antagonist, he is later an ally to Bouya Harumichi. He is the founder of the Parko and Dangerers gang. He is a friend of Kizu Kyousuke, Fujikawa Teru, and Kijima Koichi, and a former friend of Jinnai Kouhei, whom he had a falling out with.
He is a force to be reckoned with when angry, as he will attack anybody (including allies) in his sights. He has a temper and can be arrogant, but is often jovial and laid back, alongside being fiercely loyal to his friends.