Founded by Genji Kamogawa years after his retirement, the gym has two stories with a basement. The gym's structure is cubical, while in the anime it is more rectangular. On the first floor, there are a set of six windows connecting to each other, two sets of four windows in the anime. There are two horizontal sliding windows at the second floor, while there is four in the anime. On January 12, 2019, Tamura Ryoichi became the JBC Super Bantamweight Champion. He fought for the vacant title against Mugicha Nakagawa (武田勇太).

The gym then received the WBC middleweight belt by Takamura after he defeated David Eagle. Ippo had his JBC featherweight belt relinquished to move to the world stage. Takamura defeated world champion Richard Bison, making the gym acquire the WBA middleweight title. The gym also sells some Hajime no Ippo related merchandise like T-shirts, key chains, towels, and other sorted objects.

On February 14, 2000, Fukushima Manabu became the Super Bantamweight JBC Champion after defeating Yutaka Manabe. He lost the belt in his 2nd title defense to Setsuo Segawa on July 15, 2000. In Chapter 1218, Hanamori Seigo and Shintomi Ryō names appeared in the series listed from BJ Gym. Both are boxers from the JB Sports Gym.

On October 26, 2019, Kyosuke Sawada managed to defeat Kazuki Tanaka in the Strongest Challenger Tournament (Class A Tournament) [30], which secured him a spot in the Champion Carnival in 2020 with a Japanese Bantamweight title fight against the current champion Yusuke Suzuki. Yusuke Suzuki was previously one of two boxers that had defeated Sawada early in his career. On April 26, 2003, He became OPBF Champion by defeating Jae Kwang Jung for the vacant title. However, Fukushima lost his first defence match to Pederito Laurente in 12 round decision on August 16, 2003. After Ippo retired when he lost to Antonio Guevara, he became a trainer for the boxers, and Taihei Aoki and Kintarō Kaneda soon joined because of him. When Takamura defeated world champion Keith Dragon, the gym acquired the WBC super middleweight belt. Takahashi Naoto, former pro-boxer, who Miyata Ichirō is based on and friends with Morikawa, was the first coach for JB Sports, but later leaving the position in 2007. In 1969, Kamogawa opened the gym. [2] By twenty years, the gym had produced two Japanese champions and one OPBF champion, Miyata Senior. The gym also had boxing manager, Haruhiko Yagi, trainer Shinoda, boxers Mamoru Takamura, Ichirō Miyata, Baron Kurita, Masaru Aoki, and Tatsuya Kimura, however, Baron soon quit due to Takamura. Takamura invited Ippo Makunouchi to the gym, and, after sparring with Miyata, he became a member of the gym. After a second spar between Ippo and Miyata, Miyata and his father left the gym so that Miyata could face Ippo in the professional ring. Years later, the gym got a JBC middleweight belt won by Takamura, and Naomichi Yamada became a member of the gym for a short time before leaving due to having to move out of town. A JBC featherweight belt was later won by Ippo. Manabu Itagaki joined the gym, and Takamura later won the WBC junior middleweight belt until he relinquished it to move a weight class up.Itagaki mentions that the reason why Kamogawa Boxing Gym doesn't get a lot of new members is because of the "hellish training" that Takamura, Aoki, and Kimura put them through. Even Ippo unintentionally scares away new members when they see him working out. [20] The first floor and basement serve as training areas while the second floor contains Kamogawa's office. Both the first floor and basement also contain boxing rings in them. After Takamura defeated Bryan Hawk, he put a bronze statue of himself on the roof of the gym. Morikawa's gym was originally called JB Sports Club (JBスポーツクラブ), but changed the name over to JB Sports Boxing Gym. JB Sports Gym appeared in Episode 4 of Fake Affair (偽装不倫) or Gisou Furin, a Japanese Drama based on the manga with the same name. A character in the series is a boxer, and he is seen at JB Sport Gym training in the episode. However, the gym name was changed to Toyokuni Boxing Gym (豊国ボクシングジム). For their debut match, George Morikawa would act as their 2nd (which he only does part of the time.)