The noted historian Uemura Seiji, specialist in East Asian history, was his brother.

In 1920, he collaborated with Ton Satomi, Masao Kume, and Isamu Yoshii on the literary journal Ningen ("Human").

It later metamorphosed into the extremely long-running television series Mito Kōmon, which remains popular to this day and which is largely responsible for turning the historical Tokugawa Mitsukuni into a folk hero.

As well as historical novels such as Araki Mataemon and Odoriko Gyojoki, Naoki wrote biographies of historical figures — including Kusunoki Masashige, Ashikaga Takauji, and Genkuro Yoshitsune — and contemporary social fiction, including Nihon no Senritsu ("Japan Shudders") and Hikari: Tsumi to Tomoni ("Light: With Crime").

Yasunari Kawabata, with whom Naoki shared a common interest in the game of go, wrote the eulogy for his funeral.