Ever since award-winning Japanese documentary film director Masako Sakata's American husband died nearly two decades ago, she has been on a quest for answers about the tragic fallout caused by Agent Orange in the Vietnam War.

She was convinced that her partner, Greg Davis, who served three years in the U.S. military in Vietnam through 1970 and was later diagnosed with liver cancer, died as a result of his exposure to the toxic defoliant.

But what she discovered with her own eyes after repeated visits to the Southeast Asian country from 2004 would produce much more than "Agent Orange — A Personal Requiem," her first documentary film in 2007, but a Japanese-language series, culminating with her latest work, "Long Time Passing," to be released later this month in Tokyo, highlighting how the interests of government are put ahead of humanity in times of war.