He faced Anthony Birchak in the first round of the Rizin Bantamweight Grand Prix on July 30 , 2017 at Rizin 6 and won the fight via split decision .
In July 2017 , Otsuka made his debut for Rizin Fighting Federation .
Otsuka faced Anthony Birchak in the first round of the Rizin Bantamweight Grand Prix on July 30 , 2017 at Rizin 6 and won the fight via split decision .
In July 2017 , Otsuka made his debut for Rizin Fighting Federation .