Kumada started working for NHK after she graduated from university in 1993. At regional broadcasting centers, she reported on a variety of fields such as the regional events, accidents, local politics, culture and education. In 2000, she moved to CNN where she worked as a writer for one year. She then went freelance, working as a director for commercial broadcasters and NHK documentary programs about world affairs and public welfare. She rejoined NHK 5 years ago has directed travel-related and information programs. Now she is working as a producer after working on public welfare programs.