Career
Born in Gobo in Wakayama prefecture, Yukawa began his martial arts training in judo, studying under Tesshin Hoshi. He then took up the study of aikido. While a student at the Kobukan, Yukawa was known for his physical strength, earning the nickname the "Kobukan Samson".
He was strong enough to clap two sacks of rice together and bend iron nails with his hands.
Yukawa was one of only a handful of students to study with Ueshiba for more than five years. He died from stab wounds sustained during a fight with a soldier in Osaka.