Kimura was born on September 10, 1917, in
Kumamoto, Japan. Masahiko Kimura began training judo at the age of 9, motivated by revenge to get back at his teacher Mr. Tagawa, who was a 1st dan Judo Black Belt and who often scolded Kimura. He believed that if he achieved the rank of 2nd Dan, he would be able to beat Mr. Tagawa. He first earned his black belt after transferring to Chinsei Junior High, where he underwent a promotion test. In the promotion test he threw 5 students of Kumamoto Junior High, passing his test and achieving 1st dan. For his 3rd dan promotion, he had to undertake a physical and written test at the headquarters of
Butokukai in
Kyoto. Although he passed his physical test, he cheated on his written exam by writing his own name on someone else's test paper, an act he said filled him with guilt. He was promoted to yondan (4th dan) at the age of 15. He had defeated six opponents (who were all 3rd and 4th dan) in a row. In 1935, at age 18 he became the youngest ever godan (5th degree black belt) when he defeated eight consecutive opponents at
Kodokan (headquarters for the worldwide judo community). Kimura was also known to engage in street fights. In Chinsei Junior High, students proficient in martial arts would be targeted by delinquents for clout. In one instance, a member of the Judo club named Iida, met Kimura outside of school premises and attacked him with a knife. Kimura received a wound in his buttocks and chased Iida to his home. Iida's parents intervened by apologizing on his behalf. In another instance, an infamous street fighter from Kumamoto Commerce Junior High, challenged Kimura in Shimogawara park. He attacked Kimura with a
tantō short sword, but Kimura evaded the attack and performed a Judo throw on him, disarming him. No other street fighter challenged him after this incident. At one point, Kimura won eight matches in a tournament and lost his 9th bout against a Judoka called Miyajima. Ushijima sensei gave him a series of slaps and stated: "Shiai is equivalent to a real sword 'Kill or Get Killed' duel between Bushi. To throw the opponent means to kill him. Being thrown means being killed. You killed 8 men, and got killed by the 9th man. Remember, if you devote your life in judo, you can survive only by throwing your opponents or fighting to a draw no matter how many tough opponents you face." After the end of World War 2, there was a clamp down on Japanese martial arts ordered by the
GHQ, in order to suppress Japanese military nationalism. While waiting in line for a train at the
Mukomachi station, 4 men from the US Army Military Police arrived and started heckling and physically abusing Japanese people in line. When Kimura resisted they surrounded him and led him towards Nagaroku Bridge where they fought him. Kimura defeated the first MP by blocking his right punch and kicking him in the groin, he threw the second MP into a river with a
Seoi-Nage, he delivered a headbutt into the third MP and incapacitated the last MP by squeezing his balls. He later stated that he fought to defend the honor of Judo. Fearing retaliation from the Military Police he began keeping a low profile. A week later he was invited to the headquarters of the Military police by Captain Shepard, who thanked Kimura for intervening and punishing the 4 MP's, explaining that they were well known for harassing, threatening and even sexually assaulting Japanese citizens. Captain Shepard further asked Kimura to come to the MP headquarters thrice a week to teach them Judo. Captain Shepard would go on to earn a 1st degree Black Belt. He considered quitting judo after those losses, but through the encouragement of friends he began training again. He consistently practiced the leg throw
osoto gari (large outer reap) against a tree.). In his autobiography, Kimura attributes the use of the
makiwara (a karate training implement) as taught to him by So Neichu and his friend and training partner Masutatsu Oyama, as being a significant contributor to his consequent tournament success. He began using the makiwara daily prior to his first All Japan success and never lost another competition bout. ==Kimura vs. Hélio Gracie==