Kosei Tanaka

Kosei Tanaka is a former Japanese professional boxer. He was a four-weight World Champion, having held the WBO titles at Mini-Flyweight, Junior Flyweight, Flyweight, and Junior Bantamweight (Super Flyweight).

Player Profile and Personal Life

Kosei Tanaka was born on June 15, 1995, in Tajimi, Gifu Prefecture, Japan. The Japanese fighter is 164 cm tall and has a wingspan of 164 cm.

He competed in four weight divisions, from Mini-Flyweight to Super Flyweight. He fought from an orthodox position and was known for his rapid rise through the weight classes, becoming the fastest fighter in history to win world titles in four divisions (21 fights).

Career

Tanaka began his professional campaign in November 2013. He won his first world title in only his fifth professional fight, capturing the WBO Mini-Flyweight belt. He continued to make history by winning the WBO Junior Flyweight title in his eighth fight and the WBO Flyweight title in his 12th fight, equaling Vasiliy Lomachenko's record for fastest to three divisions.

In February 2024, he defeated Christian Bacasegua to win the vacant WBO Super Flyweight title, becoming a four-division champion.

His career ended following a loss in his first defense of the Super Flyweight title. In October 2024, he lost a split decision to Phumelele Cafu in Tokyo. Following the bout, Tanaka announced his retirement in June 2025 due to recurring eye injuries that required surgery and threatened his vision.

Career Record:

Total - 22

Wins - 20

• By knockout - 11
• By decision - 9

Losses - 2

• By knockout - 1
• By decision - 1

Draws - 0

Medal Record

• 2013 - Subic Bay Asian Youth Championships, Men’s Junior Flyweight, Silver
• 2012 - National High School Selection Tournament, Light Flyweight, Gold
• 2013 - National High School General Athletic Meet, Light Flyweight, Gold