Koyoharu Gotouge is a pseudonymous Japanese manga artist best known for creating the immensely popular manga series "Demon Slayer: Kimetsu no Yaiba." As of my last update, there isn't extensive publicly available information about their personal life or biography. Gotouge's real identity, including their gender, has not been officially disclosed. 

"Demon Slayer: Kimetsu no Yaiba" debuted in 2016 and quickly gained widespread acclaim for its compelling story, memorable characters, and stunning artwork. The series follows Tanjiro Kamado, a young boy who becomes a demon slayer after his family is slaughtered by demons, and his quest to avenge their deaths and cure his sister, Nezuko, who has been turned into a demon.

The manga achieved immense commercial success and garnered a massive fanbase both in Japan and internationally. Its popularity skyrocketed further with the release of an anime adaptation produced by Ufotable, which aired from April to September 2019. The anime adaptation received critical acclaim for its animation quality, music, and faithful adaptation of the source material.

In addition to the manga and anime, "Demon Slayer: Kimetsu no Yaiba" has spawned various merchandise, video games, and a successful animated film titled "Demon Slayer: Kimetsu no Yaiba the Movie: Mugen Train," which became one of the highest-grossing films of all time in Japan.

Gotouge's work on "Demon Slayer" has solidified their place as one of the most prominent figures in the manga industry. However, they have maintained a low public profile, preferring to let their work speak for itself.