Nomura was born in the rural district of Shiwa county, Iwate prefecture in northern Japan, the younger son of a farmer.

He was sent to boarding school in Morioka, where he met Kindaichi Kyosuke, later a noted linguist and Namura's lifelong friend.

While working as a journalist, Nomura began to write popular fiction, notably historical novels, which appeared in serialized form in the literary journal Bungei Shunju.

The main characters in the story were modeled after Sir Arthur Conan Doyle's famous detective pair, Sherlock Holmes and Dr Watson.

He had previously (in 1956) donated his entire library to his home town of Shiwa in Iwate prefecture, where it now resides in a memorial museum erected in his honor.