Some of his work include the Langrisser, Lunar, Grandia, and Ace Attorney series.

Iwadare was born in Matsumoto City, Nagano Prefecture, Japan.

He began to compose video game music after years of being involved with university bands.

He began composing for Toaplan, arranging their arcade video game soundtracks for their Sega Mega Drive home console ports, notably the Mega Drive version of Zero Wing (1990), before composing for other companies such as Game Arts on their Lunar and Grandia series.

He was a special guest at the 11th French Japan Expo that was held in July 2010 in Paris.