Kōichi Wajima (輪島 功一, Wajima Kōichi) is a retired Japanese professional boxer and a former WBA and WBC super welterweight champion. He is known for his unique "Frog Jump" punch he used against WBA and WBC super welterweight champion Carmelo Bossi, who he defeated by decision.
References in Hajime no Ippo[]

Kōichi Wajima being referenced in the manga.
- In Round 4, after Ippo Makunouchi's first spar against Ichirō Miyata, Haruhiko Yagi was impressed by Ippo's determination. Genji Kamogawa commented that attitude boxers don't sell well. However, boxers like Fighting Harada, Masao Ohba, Hiroyuki Ebihara, and Wajima did. He added how the old boxers despite being beaten, they still stood up again and again, because of that, their dreams were born.
- In Round 443, after Masaru Aoki read that Katsutaka Imae planned on crushing his Frog Punch, he mentioned that Wajima is the person he most admired, and that it was his triumphant punch.
- Mamoru Takamura pointed out that Wajima won the world title three times, where Aoki can't compare his frog to his, as a king frog is different from a puny frog.