Yuzo Koshiro's well regarded career in the video game industry began in 1986 when he worked as a composer for the Nihon Falcom company. With Nihon Falcom, Koshiro worked on several Dragon Slayer games, including Sorcerian, and games from the Ys franchise, including Ys I and Ys II, alongside Mieko Ishikawa.
After leaving Nihon Falcom, Koshiro pursued freelance work and became well known during the 16-bit era for his composition on a number of popular Sega Genesis and Super Nintendo games such as ActRaiser, ActRaiser 2, Super Adventure Island, The Revenge of Shinobi, Beyond Oasis and Streets of Rage I, II, and III. He also made contributions to Sonic the Hedgehog, Super Smash Brothers Brawl, and Shenmue (Dreamcast).
In 1990, Koshiro helped start the Ancient Corporation, a game development studio with a heavy emphasis on music composition, no doubt reflecting Koshiro's influence. His sister, Ayano Koshiro, is a character designer at the company.
More recently, Koshiro's career has focused on handheld games for the Nintendo DS. In fact, Koshiro has made few games for current generation consoles, Wangan Midnight for the PS3 being a lone exception. Notable recent games Koshiro has worked on include Castlevania: Portrait of Ruin, 7th Dragon, and Etrian Odyssey I, II, and III.
Keeping the Classic Sound Alive: An Interview with Yuzo Koshiro
Yuzo Koshiro at Wikipedia