Novelist and former Upper House lawmaker Akiyuki Nosaka, best known for his award-winning "Grave of the Fireflies," died Wednesday at a hospital in Tokyo due to heart failure, police sources said Thursday. He was 85.

Nosaka had been undergoing rehabilitation after a stroke in 2003.

After surviving the U.S. air raids on Kobe toward the end of World War II, Nosaka dealt with the war in many of his works.

"Grave of the Fireflies" and "America Hijiki," semi-autographical tales set in the aftermath of the war, won him the Naoki Prize, one of the most prestigious literary awards for popular novels, in 1968.

Nosaka was a native of Kamakura, Kanagawa Prefecture, and began his career as a script writer and lyricist for commercial songs while a student at prestigious Waseda University in Tokyo, which he later quit.

He won the Japan Record Award in 1963 for penning the lyrics to the children's song "Omocha no Cha Cha Cha" ("Toys Dance the Cha Cha Cha") shortly before debuting as a writer with "The Pornographers."

In 1980, Nosaka was convicted and fined for releasing obscene material as a magazine editor.

He turned to politics and was elected to the House of Councilors in 1983, but lost his seat after running in a House of Representatives election held the same year against the late former Prime Minister Kakuei Tanaka, in a constituency in Niigata Prefecture.