|Birth date||July 30, 1953|
|Occupation||Naniwa Kentou-kai trainer|
|Wins by KO||?|
|Manga Debut||Round 88|
|Anime Debut||Round 30 (The Fighting)|
|Voice Actor||Tatsuta Naoki|
Yanaoka is a first class trainer and second whose skills are even recognized by Kamogawa Genji. He is one of the few people who truly understands Sendou. Yanaoka began his career as a boxer and eventually became 1st ranked in Japan, but was defeated by OPBF champion Miyata. After retiring he became a trainer at the Naniwa Kentou-kai.
Years later, a few of his trainees got beaten up by a delinquent named Sendou Takeshi(Who Yanaoka almost knocked out). After Sendou took part in another rumble, Yanaoka turned him onto boxing as a way to find the strength he hungers for.
- Although it is yet to be revealed in the manga, one of the video games lists his full name as Yanaoka Kazuhiro (柳岡かずひろ).