Toru Nakagawa (February 14, 1919 – September 24, 2002), known by his pen name Tetsuya Ayukawa (鮎川 哲也, Ayukawa Tetsuya), was a Japanese literary critic and novelist. He is noted for his Detective Onitsura Series of mystery stories.
Source: “Tetsuya Ayukawa”, English Wikipedia (CC BY-SA 4.0), excerpt