Todaka won his fight in December, 1998 to obtain a world ranking, but Iida lost to Jesus Kiki Rojas the same day to lose his WBA Super flyweight title.
Todaka made an aggressive start, giving the veteran champion a challenging fight in the early rounds.
Todaka won back the later rounds of the fight, and the judges awarded him a close, but unanimous victory to make him the new WBA super flyweight champion.
The defense took place in Tokyo on November 7, 1999, and despite the reputation Nago had built up going into the fight, he seemed nervous in his first world title match, and was unable to land his powerful right hook.
In addition to his eye injury, Todaka also broke his jaw in the fight, which forced him into a long period of inactivity.
Todaka spent all of 2001 to recover, and finally made his comeback in March 2002, winning three fights to regain his world ranking.
In the end, Todaka won a close 2-1 split decision victory, avenging his previous loss, and becoming the 5th Japanese boxer to win world titles in two different weight classes.
Todaka had planned on having a unification bout with the WBA bantamweight champion, but was unable to come to terms with promoters, and decided to make a defense instead, which was set on March 6, 2004, against Julio Zárate.
He spent the entire fight trying to catch up to the challenger, and lost by unanimous decision to lose his interim title after only five months.