Mikoto Yamaguchi is a Japanese manga writer and original creator born on September 8, 1979, in Fukuoka Prefecture. His career began with recognition in the early 2000s, becoming a finalist for the Jump Twelve Newcomer Manga Award in 2005 and winning an encouragement award in Monthly Shonen Gangan’s Gangan Cup in 2006. He made his formal debut in 2008 and began a period of consistent serialization in 2012 with the action series Gun x Clover, setting the stage for a career defined by prolific output across multiple genres and publishers.

As an original creator, Yamaguchi is known for working on numerous manga as the writer, often collaborating with different illustrators. His body of work is extensive and includes some of the most notable psychological and suspense titles of the 2010s. He is credited as the original creator for the manga Tomodachi Game, which became one of his most successful properties, later inspiring a live-action television series and two live-action films. Other major works he has authored include the violent and controversial Dead Tube, the horror-tinged drama Shinigami-sama ni Saigo no Onegai wo, and the supernatural mystery Mayonaka no X Giten. His bibliography also features titles like the action-comedy Kurenai no Assassin, the dark fantasy Saiteihen no Otoko, and the series Game of Familia. For the manga Who Wants to Marry a Billionaire? which was serialized on Kodansha’s Comic Days platform from June 2019 to January 2022, Yamaguchi provided the story while the artist Mario handled the illustrations; the series was later published in English by Seven Seas Entertainment under its Ghost Ship imprint.

Across his various works, Yamaguchi has developed a distinct artistic identity centered on psychological tension, moral ambiguity, and high-stakes scenarios. His stories frequently explore dark themes, often incorporating elements of death games, extreme survival situations, and intricate plots marked by significant twists. Tomodachi Game and Dead Tube are prime examples of this tendency, focusing on how ordinary individuals are forced into desperate circumstances that test the limits of their ethics and relationships. While many of his series fall into the seinen demographic, his genre range is broad, encompassing harem comedies like Gun x Clover, drama, horror, and ecchi, demonstrating a versatility that has allowed him to maintain a sustained and significant presence in the industry.