Hidemasa Tanaka, a KODOKAN 5th Dan Black Belt, was born in Yokohama, Japan.

He began practicing judo at the age of four. After graduating from Toin Gakuen High School, he attended Saitama University, where he participated in the national tournament for the first time.

Upon completing his university education, Tanaka worked as a teacher in Yokohama. In 2001, he became a physical education teacher at Nara Junior High School and began advising the school’s judo club in 2003. Despite his busy teaching schedule, which limited his judo practice to two or three times a month, Tanaka continued to compete. He placed third in the Kodokan Cup in 2001 and won the same tournament in November 2002, marking his first All-Japan championship. In January 2003, he placed third in the Kano Cup and later that year, he secured third place in the All-Japan Weight Class Championship, making him a candidate to represent Japan in the 73 kg class at the Athens Olympics.