Furokawa, better known as Bull or Bull the Infinite, is a punk and an outsider to the world of martial arts. His nickname is derived from the pronunciation of Furu, which sounds like Buru. He is a minor character throughout the series, either seen trying to become tougher, or as a victim to Joukyuu Kunitoshi's jokes.
He has blond hair and a short goatee. Often sports sunglasses and dresses like a punk/hoodlum.
Furokawa is the usual tough-guy type who has a dream of becoming the head of the Japanese yakuza one day. He has a moral code that prevents him from hitting girls and has since the beginning of the series been humiliated countless times by Joukyuu and his group.
He has no martial art skills, but is an experienced boxer. He once hired Joukyuu to teach him how to lay a single punch on Shikae in exchange for 1 million yen. The deal was later cancelled when Furokawa left only partly done with the training, however with the little training he did receive, he still managed to lay a blow on Shikae. He was later trained by The General to some extent.
Furokawa was first introduced as a student from the neighbour town who tried to invade the Juuzenji Private Highschool, so Takatori Miu set him up to fight Joukyuu. After being humiliated, Furokawa later interrupted a fight between Shikae, and Kizuki Rin and Takatori Miu, and tried to fight him with his henchmen. Shikae knocked all of his henchmen out, but kept him conscious to give him a warning not to ever interfere in a martial arts fight again.  After this incident, he persuaded Joukyuu to teach him how to land a single blow on Shikae.
During Joukyuu and Karasumaru's final battle, Shikae was hiding in the background, waiting for the perfect moment to strike a severely wounded Joukyuu, and gain a name for himself by defeating him. However, as Shikae was going to take out Joukyuu, Furokawa suddenly dropped in and utilized the one move Joukyuu had taught him perfectly, evading one of Shikae's blows and subsequently dealing one to him in return. Shikae, while in shock, didn't notice that Joukyuu still had some power left in him and was taken out by Joukyuu in the end. Joukyuu praised Furokawa, but said he could have taken out Shikae even without his help.
Furokawa was later seen being imprisoned by Veronica's mercenaries after being abandoned by Joukyuu in an unnamed country. He was then taken under The General's wing, who had similar motivations as him to take down Joukyuu. After Catacomb set up the ammunitions storage in Veronica's base to blow, The General, while badly wounded, threw Furokawa outside and saved him from the collapsing building.
Furokawa was later seen in Japan working as an errand boy for the yakuza. Once his superior was beaten by Joukyuu and his group, he reluctantly agreed to come with them to a martial arts tournament in America. With nobody having any knowledge of who he was, Joukyuu introduced him as "Bull the Infinite", a legendary war god who trained for 50 years before coming out in the open. Joukyuu then helped him fight Shikae, by guiding his movements from behind.