Boxing: Injury-hit ex-WBO minimumweight champ Ryuya Yamanaka retires
OSAKA (Kyodo) -- Former WBO minimumweight boxing champion Ryuya Yamanaka, who returned to the ring after suffering a severe brain injury, has retired,
Tomas Kauer - News Moderator 
OSAKA (Kyodo) -- Former WBO minimumweight boxing champion Ryuya Yamanaka, who returned to the ring after suffering a severe brain injury, has retired,
