Height: 1.69 m (5 ft 7 in)
Weight: 73 kg (161 lb; 11.5 st)
Birthdate: 12 September 1969
College: Nihon University
Year turned pro: 1992
Birthplace: Ichikawa, Chiba, Japan
Born in Ichikawa, Chiba, Japan, Maruyama went to Nihon University after high school, before turning professional in 1992. He is well known for his ever-present grin on the fairway which has earned him the nickname of the "Grinning Assassin". Maruyama started his professional career playing on the Japan Golf Tour, and he very rapidly became one of the main players on that tour. In 1999 he played exceptionally well in two World Golf Championship events, and earned himself a place on the PGA Tour. After joining the Tour, Maruyama achieved victory on three occasions. Despite his high playing standard on the Tour, Maruyama did not sustain his appearance rate and returned to play in Japan during the 2088 season.
Away from individual golf, Maruyama was a member of the International Team in the Presidents Cup in 1998 and 2000.
While qualifying for the US Open in 2,000 Maruyama shot a 58 in the first round. His father named a golf course in Tochigi Prefecture, Japan the 58 Golf Course, in recognition of this achievement.
As of the end of 2014, Maruyama had achieved 3 wins on the PGA Tour, amassing total prize money of $13,809,172.