Eiji Kojima, born on December 16, 1977, in Hiroshima, Japan, carved out a brief but eventful career in professional boxing during the early 2000s. Standing at 5 feet 7 inches and fighting out of a southpaw stance, Kojima combined technical ability with resilience, earning his place among Japan's most respected super-flyweights of his time. While his time at the elite level was short-lived, it was punctuated by moments of triumph and hard-learned lessons against world-class opposition.
Kojima entered the professional ranks on December 12, 2000, in Osaka, where he faced Tatsuya Imazu. After four rounds, the bout ended in a technical decision win for Kojima, marking the start of his professional journey.
His rise to prominence came in his fifth professional outing on December 3, 2001, when he captured the vacant OPBF Super Flyweight Title by outpointing Keun Shik Lee via technical decision. This regional triumph showcased Kojima's sharp skills and ring IQ. He solidified his status with a unanimous victory over Hayato Asai on April 14, 2002, in Nagoya, successfully defending his title.
The turning point in Kojima's career arrived on July 31, 2002, when he stepped up to challenge Venezuela's Alexander Muñoz for the WBA World Super-Flyweight Title in Osaka. Muñoz, an undefeated knockout artist, overwhelmed Kojima with his ferocious power, stopping the Japanese southpaw in the second round. It was a humbling defeat that demonstrated the gulf in experience and firepower between the two fighters.
Despite the setback, Kojima returned to the regional circuit and rebuilt his confidence. On August 16, 2003, he reclaimed the vacant OPBF Super Flyweight Title with a split-decision win over Waen Lertsungnern in Osaka. This victory earned him another shot at Alexander Muñoz in a rematch on January 3, 2004, at the Central Gym in Osaka. Kojima fought with undeniable courage but was again outclassed, suffering a stoppage in the tenth round after being knocked down multiple times throughout the bout.
The physical and mental toll from back-to-back defeats against a world-class champion seemed to linger. On May 2, 2004, Kojima faced Waen Lertsungnern in a rematch for the OPBF Super Flyweight Title. This time, the Thai fighter avenged his previous loss with a crushing second-round knockout, signalling the decline of Kojima's brief but intense career at the top level.
Kojima's final professional fight occurred on January 29, 2005, against Nobuaki Naka in Osaka. In a ten-round contest, Kojima displayed his remaining grit and experience, securing a unanimous decision victory. It was a respectable end to a turbulent career that had seen him rise to regional dominance, challenge world honours, and experience the unforgiving reality of championship-level boxing.
Retiring with a professional record of 12 wins, 3 losses, and 3 knockouts in 15 bouts, Kojima left the sport with the respect he deserved.