Popular mixed martial arts fighter Norifumi "Kid" Yamamoto passed away from cancer, the Twitter account of his gym Krazy Bee announced on Tuesday. He was 41 years old.

With a wrestling background and aggressive striking-oriented fighting style, Yamamoto became a top fighter in Japanese promotions such as HERO'S and K-1. He took the ring for the Ultimate Fighting Championship in the United States as well.

The Kawasaki native revealed he had cancer in an Instagram post late last month, but the type of cancer was not given.

Yamamoto's older sister Miyu and younger sister Seiko are both former world wrestling champions. Seiko is major league pitcher Yu Darvish's wife.