Romeo Tanaka is a Japanese author and scenario writer, born on June 6, 1973, in Ishikawa Prefecture, Japan. He is known for his work across different media, including visual novels, light novels, manga, and anime. At one time, he attended the University of Tsukuba.

Tanaka is the original creator of the story Aura: Koga Maryuin's Last War. He wrote the original light novel, which was published by Shogakukan under their Gagaga Bunko imprint on July 18, 2008, with illustrations by Mebae. This light novel serves as the source material for subsequent adaptations. A manga adaptation, for which Tanaka is credited as the original author, was illustrated by Kōichirō Hoshino and serialized in Shogakukan's Shōnen Sunday S magazine from February 25, 2012, to March 25, 2013, spanning four collected volumes. An anime film adaptation produced by AIC ASTA and directed by Seiji Kishi premiered in Japanese theaters on April 13, 2013.

Beyond his work on Aura, Tanaka has a significant portfolio as a creator. He began writing his first light novel series, Humanity Has Declined (Jinrui wa Suitaishimashita), in 2007, also published by Shogakukan. In the visual novel industry, he is notable for his scenario writing on titles such as Cross Channel and Yume Miru Kusuri, and he co-authored the scenario for Key's game Rewrite. He has also worked under the pseudonym Hajime Yamada.

Tanaka is recognized within the industry for his distinctive narrative voice, which often blends philosophical themes, dark science fiction, and a cynical yet witty tone. His works, particularly Cross Channel, have been cited as influential by other prominent creators in the Japanese game and light novel writing community.