Hiroko Maruyama is a veteran Japanese voice actress born on October 22, 1946, in Tokyo. She began her career after training at the Toho School of Performing Arts for one year, subsequently joining the theatre company Teatro Echo in 1966, with whom she remains affiliated. Her career has spanned from the late 1960s into the 2010s, demonstrating her longevity and versatility in the industry.

Maruyama is known for a wide array of roles, often voicing young boys, animals, and unique characters. In her early career, she voiced U-ko in the 1971 series Shin Obake no Q-Tarō and took on the titular role of Robotan in the 1966 anime, a part she would reprise in the 1986 series. She is also recognized for her work in classic family fare, such as providing the voice of Peter in the 1974 series Alps no Shōjo Heidi. Her filmography includes roles in numerous productions from the 1970s and 1980s, a golden era of anime. She voiced the character Gon in Hajime Ningen Gyatoruz (1974) and played the role of Abacchi in Konchu Monogatari Shin Minashigo Hutch. In the popular series Ninja Hattori-kun, she was the voice of Togejirou, a role she reprised in several films, including Ninja Hattori-kun + Perman: Chō-Nōryoku Wars. For fans of sports anime, she is well-known as the voice of Ryo Ishizaki in the original 1983 Captain Tsubasa series. She also played Mitsugu in the long-running series Cooking Papa.

Beyond television, Maruyama contributed to several notable theatrical films. She appeared in two Hayao Miyazaki-directed films, providing the voice for Kanta's mother in My Neighbor Totoro (1988) and a small role in Kiki's Delivery Service (1989). Her film work also includes roles in the Panda! Go, Panda! films, where she voiced Nana (Baby Panda) in the second movie, Panda! Go, Panda!: Rainy Day Circus (1973). She was also the voice of Onabe in the film 21 Emon: Uchū e Irasshai!. Her filmography includes the role of Tae-su in Kim no Jūjika, Moko in The Story of Fifteen Boys, and the cat in 11 Piki no Neko to Ahoudori.

Maruyama's work extended into live-action tokusatsu productions, where she voiced the character Mag in the 1986 series Choushinsei Flashman. She also voiced the title character in the puppet drama Pettonton in 1983. Her talent was not limited to voice acting, as she also took on a live-action role, playing Otsune in the acclaimed 1983 television drama Oshin.

Throughout her decades-long career, Maruyama's achievements reflect her status as a foundational figure in Japanese voice acting, contributing her voice to some of the most beloved and iconic series and films in the medium.