Sensei Keiko Fukuda has become the first woman to achieve a tenth-degree black belt in judo - at the age of 98.

The highest rank in the martial art and combat sport, Fukuda joins just three other living people - all men living in Japan - who've earned the "dan" black belt. She is also one of just 16 people in history to have achieved this honor.

Fukudo's story is quite remarkable.

She is the sole surviving student of judo's founder, Kano Jiguro, and began practicing the sport back in 1935.

At a time when getting married and starting a family was the norm, Fukudo shunned marriage in pursuit of martial arts.

Fukuda said in the recent documentary about her life, "Be Strong, Be Gentle, Be Beautiful": All I did was judo. ... This was my marriage. This is when my life destiny was set. I just never imagined how long this road would be."

She is credited for spreading judo internationally after Jiguro urged her to learn English.

Fukuda continues to teach judo three times a week at a women's dojo in San Francisco.

Despite her fondness for judo's founder, Fukuda has been vocal about Jiguro's school, calling it "old-fashioned and sexist about belts and ranks."

Fukuda was kept at a subordinate level in the sport for decades due to an edict that prevented women from achieving any higher rank than a fifth-degree black belt. She watched as men less skilled than she moved up the ranks.

"All my life," Fukuda told the San Francisco Chronicle, "this has been my dream."

Watch a clip from "Be Strong, Be Gentle, Be Beautiful:"