Nishio is a Japanese director of animated films and series, most famous for his work on the Dragon Ball series. He began his career in 1981 in the Toei Animation studio. He directed several anima TV series, he was assistant director on Dr. Slump in 1982, and in the mid-1980’s directed several parts of the Dragon Ball (1986) series. He also directed the first film Dragon Ball: Curse of the Blood Rubies (Doragon bôru: Shenron no densetsu, 1986). After two more films of the Dragon Ball series, he directed several Dragon Ball Z films: Dragon Ball Z: Dead Zone (Doragon bôru Z, 1989), Dragon Ball Z: The Movie - The World's Strongest (Doragon bôru Z: Kono yo de ichiban tsuyoi yatsu, 1990), Dragon Ball Z: The Movie - The Tree of Might (Doragon bôru Z 3: Chikyû marugoto chô kessen, 1990), Dragon Ball Z: The Return of Cooler (Doragon bôru Z 6: Gekitotsu! Hyakuoku pawâ no senshi, 1992), Dragon Ball Z: Super Android 13 (Doragon bôru Z 7: Kyokugen batoru!! San dai sûpâ saiyajin, 1992). From 1996 to 1999 he directed the TV series Dragon Ball Z.