He is best known for creating the soundtracks for the Heisei Gamera trilogy, Godzilla, Mothra and King Ghidorah: Giant Monsters All-Out Attack, Mobile Suit Gundam Wing, and Shadow of the Colossus.

The company has grown to feature musicians like Kohei Tanaka, Shiro Hamaguchi, Hayato Matsuo, and Shinji Miyazaki, who have become well known for cinematic scoring and orchestration through Otani.

In 1987, he made his debut as an anime composer with the popular manga adaptation City Hunter, which earned him recognition in the industry.

The anime Future GPX Cyber Formula (1991) and Mobile Suit Gundam Wing (1995) and several films in the Gamera series are some of his most well-known works.

[1] He appeared at Eminence Symphony Orchestra's events A Night in Fantasia 2007: Symphonic Games Edition and Unearthing Eden ~The sounds of AINARU~ in 2007.