Kosei Tanaka has vacated his WBO junior flyweight title.
Tanaka and promoter Kiyoshi Hatanaka have expressed the fighter’s intent on moving up in weight to the flyweight division and WBO President Francisco Valcarcel was sent a letter to make the move official.
"We, Tanaka and I, express our utmost appreciation of your precious guidance and leadership in Tanaka having acquired the WBO 105-pound and 108-pound championships, and sincerely wish that the WBO will newly rank Tanaka in the 112-pound category so that he will try to obtain his third WBO belt," the letter stated.
WBO guidelines does grant a boxer immediate mandatory challenger status if he vacates his world title and decides to move up in weight to fight for that world title. Tanaka has been out with a jaw injury for some time, last fighting on September 13, beating Rangsan Chayanram via TKO to retain his title. Tanaka has held the WBO title since December 31, 2016 when he stopped Moises Fuentes inside five rounds to capture the title.
As for the status of the title, the Angel Acosta vs. Juan Alejo fight was named as the fight to crown a new WBO champion. That fight was originally scheduled to be for the vacant interim WBO junior flyweight title on the Miguel Cotto vs. Sadam Ali HBO undercard, but the announcement has upgraded Acosta vs. Alejo to a world title fight.
Tanaka, who is just 22 years old, is 10-0 as a pro boxer and has won world titles at minimumweight and junior flyweight. The current WBO flyweight champion is fellow Japanese boxer Sho Tanaka, who won the title back in July.