is a Japanese screenwriter and novelist focusing on anime productions. His name was written as until 1987.
He graduated from Waseda University in 1972 and joined to Tatsunoko Production as a story creator and a screenwriter. He left from Tatsunoko in 1975, but he was related to the Time Bokan series, one of the most successful anime series of Tatsunoko, from Time Bokan in 1975 to the last series, Itadakiman in 1983. After leaving from Tatsunoko, he wrote several screenplays such as Captain Tsubasa, Dragon Ball and Saint Seiya of Toei Animation.
In parallel with works as screenwriter, he is endeavoring to bring up young talents. In 1986, he found "Anime Scenario House" to train the young anime scenario writers. By 1987, young screenwriters such as Satoru Akahori, Hiroyuki Kawasaki, Katsuyuki Sumisawa, Keiko Nobumoto and Aya Matsui graduated from Koyama's school. The school became Brother Noppo, company to support screenwriters, in 1988.
Koyama authored a remake of Akira Toriyama's Soldier of Savings Cashman manga, that was illustrated by Katsuyoshi Nakatsuru and serialized in V Jump from June 1997 to December 1998.[1]
| Year | Title | Studio | Note |
|---|---|---|---|
| 1981–1982 | Yattodetaman | Tatsunoko | Part of Time Bokan franchise. |
| 1981–1982 | Urusei Yatsura | Studio Pierrot | Episode 1 to 21. Replaced by Kazunori Ito. |
| 1982–1983 | Ippatsuman | Tatsunoko | Part of Time Bokan franchise. |
| 1982 | Don Dracula | Tezuka Productions | — |
| 1984 | Starzan S | Tatsunoko | — |
| 1985–1986 | Showa Aho Zōshi: Kanuke Ichiban! | Tatsunoko | — |
| 1986–1988 | Saint Seiya | Toei Animation | Episode 1 to 73. Replaced by Yoshiyuki Suga. |
| 1986–1987 | Doteraman | Tatsunoko | — |
| 1987 | Red Photon Zillion | Tatsunoko | — |
| 1987–1989 | Dragon Ball | Toei Animation | Episode 83 to 153. Replacing Toshiki Inoue. |
| 1987 | Project A-Ko 2 | A.P.P.P. | Sequel to Project A-Ko. |
| 1989–1990 | Kojiro of the Fuma Clan | J.C. Staff Animate Film | — |
| 1989–1990 | Legendary Idol Eriko | Ashi Productions | — |
| 1989–1996 | Dragon Ball Z | Toei Animation | Sequel to Dragon Ball. |
| 1990–1991 | Mashin Hero Wataru 2 | Sunrise | Sequel to Mashin Hero Wataru. |
| 1990–1991 | Figures of Happiness | Production I.G | — |
| 1991 | I Am Chokkaku!! | Studio Pierrot | — |
| 1992–1993 | Floral Magician Mary Bell | Ashi Productions | With Hideki Mitsui. |
| 1993–1994 | The Brave Express Might Gaine | Sunrise | Part of Yūsha franchise. |
| 1993–1994 | Willow Town | E&G Films | — |
| 1995 | Slayers | J.C. Staff E&G Films | First season only. |
| 1996 | The Life and Adventures of Santa Claus | Studio Deen | — |
| 1998 | Legend of Basara | Yumeta Company | — |
| 2001–2002 | Offside | Ashi Productions | — |
| 2009–2015 | Dragon Ball Z Kai | Toei Animation | |