Kosei Tanaka is a Japanese former professional boxer who competed from 2013 to 2024. He is a four-weight world champion, having held the World Boxing Organization mini-flyweight title from 2015 to 2016; the WBO junior-flyweight title from 2016 to 2017; the WBO flyweight title from 2018 to 2020; and the WBO junior-bantamweight title in 2024. From Wikipedia
