Flyweight
The lightest division contested internationally, and the deepest in Japan.
Flyweight is where the Japanese domestic scene is strongest. RISE, Krush and the revived K-1 all run divisions here, and the technical standard is arguably the highest in the sport — at this weight almost nobody ends a fight with a single shot, so rounds are decided by volume, timing and defence rather than power.
The divisional limits diverge more than they look. K-1's 55 kg is a genuinely different fight from GLORY's 57 kg; two kilos at this end of the scale is a meaningful share of bodyweight, and fighters move between the two by cutting rather than by stepping up.
Women's flyweight has been one of GLORY's more competitive divisions, with Denise Kielholtz building one of the best win rates in the sport there.