Masahiro Shimizu (清水 雅広, Shimizu Masahiro; born November 22, 1964) is a Japanese former professional Grand Prix motorcycle road racer. Originally from Fujisawa, Kanagawa Prefecture, Shimizu won the 1987 250cc All Japan Road Race Championship. He began his Grand Prix career with a win in 1987. His best season was in 1991, when he finished fifth in the 250cc world championship, riding on a Honda.
Source: “Masahiro Shimizu”, English Wikipedia (CC BY-SA 4.0), excerpt