Veteran novelist Fumio Niwa, whose works depicted modern life and historic Buddhist monks, died of pneumonia early Wednesday morning at his home in Musashino, western Tokyo, his family said. He was 100.

Niwa dedicated his literary career to writing about modern life from the 1930s until after World War II. But after turning 60, he also wrote novels with religious themes, including "Shinran" in 1969 and "Rennyo" in 1982-1983. Shinran was a noted Japanese Buddhist monk in the 12th-13th centuries and Rennyo was a monk in the 15th century.

After graduating from Waseda University, Niwa succeeded his father as the priest of a Buddhist temple in Mie Prefecture. But he left the temple for Tokyo in 1932, and later debuted in the literary circle with "Ayu" ("Sweetfish"), a short story about his parents.

His stories dealt with such topics as rich housewives and bar hostesses as well as telling stories based on his family.

One of his best-known novels is "Iyagarase no Nenrei" ("The Hateful Age"), about a wicked old woman and her family. It was published in 1947.

Niwa was regarded as a patriarch in Japanese literary circles and headed the Japan Writer's Association for a long time. The government awarded him the Order of Culture in 1977.

His family revealed that he had been under nursing care for Alzheimer's disease since about 1986.