Since March 2007, Mamoru officially became a newbie of the Neoromance events held by the Japanese game company Koei by voicing Aoi Kaji in the Kiniro no Corda 2 PS game.
Mamoru is an avid singer and has done an ED single for Kotetsu Sangokushi and a Tamaki character single for Ouran High School Host Club.
Mamoru has done work for several drama CDs, including the roles of Zero Kiriyuu in Vampire Knight and Seiju Shikibu in Dolls.
Mamoru plays both the harp and the harmonica.
Mamoru's Japanese dubbing work includes Percy Weasley in the Harry Potter series, Tyler in E.T. the Extraterrestrial, and Jack Conroy in White Fang.
At the first Seiyu Awards, Mamoru received two nominations for his role as Light Yagami: Best Main Character (Male) and Best Rookie (Male).
Mamoru likes to play and watch soccer.
Mamoru is 182cm tall and weighs 58kg.
Mamoru's blood type is B.
Mamoru's video game voice work includes Moondoggie in the Eureka Seven: TR2:NEW VISION video game, Aoi Kaji in La Corda d'Oro 2, Jade in Summon Night Craft Sword Monogatari: Hajimari no Ishi, Shu Kunisaki in Trouble Fortune: Company Happy Cure, and Riku in the Kingdom Hearts series.
Mamoru played Ishida Tetsu in The Prince of Tennis musicals and Renji Yanagi in The Prince of Tennis film.