Hiroyuki Agawa was a Japanese author born on December 24, 1920, in Hiroshima, Japan. He died on August 3, 2015. Agawa studied Japanese literature at Tokyo Imperial University before being conscripted into the Imperial Japanese Navy during World War II, where he served as an intelligence officer. After the war, he returned to Hiroshima and began his literary career, establishing himself as a prominent novelist, biographer, and essayist.

Agawa is recognized for his fiction centered on World War II and for authoritative biographical works on key figures in modern Japanese history. Among his notable books are the novel Citadel in Spring, which won the Yomiuri Prize, and the biography Yamamoto Isoroku, which received the Shincho Literary Prize. His other major biographies include works on Yonai Mitsumasa, Inoue Seibi, and the writer Shiga Naoya. In recognition of his contributions to literature, Agawa was awarded the Order of Culture in 1999.

His role as an original creator for anime stems directly from this literary career. He is credited as the original work creator for the anime film Kikansha Yaemon: D51 no Daibouken, which was released in 1974. This credit signifies that the film was adapted from an existing story or concept originated by Agawa, rather than being an original screenplay written specifically for the screen. This work is a representative example of his storytelling being adapted into the anime medium.

Throughout his body of work, recurring themes include autobiographical reflections on his wartime experiences and the profound impact of World War II on Japanese society. His literary identity is also defined by his meticulous biographical works, which blend documentary detail with narrative craft. His significance in the Japanese cultural landscape is marked by his receipt of major literary awards and the high regard for his biographical novels, which are considered definitive accounts of their subjects. He is also the father of the author and television personality Sawako Agawa.