Hidekazu Mashima was born in Yonezawa, Yamagata, Japan on November 13, 1976. He started getting interested in films because of the influence of friends when he studied law at Kokushikan University in Tokyo. He took acting classes and received the offer of a leading role in Sang-il Lee's graduation project, Chong (2000). After the debut, he dropped out of law school regardless of the disagreement of his parents and stayed in Tokyo to keep pursuing his acting career.