Tenichi is a Japanese author best known for creating the light novel series The Most Heretical Last Boss Queen: From Villainess to Savior. This series began as a web novel on the Shōsetsuka ni Narō website in April 2018, where it first gained popularity before being acquired for print publication.

The professional writing career of Tenichi achieved early recognition when the series won Ichijinsha’s Iris NEO Award, a distinction that led to its official release as a light novel. The print version, illustrated by Suzunosuke, has been published by Ichijinsha since June 2019, with the English-language edition released by Seven Seas Entertainment. The series has since expanded into a multimedia franchise with multiple adaptations.

The manga adaptation of The Most Heretical Last Boss Queen: From Villainess to Savior was illustrated by Bunko Matsuura and serialized on the Zero-Sum Online platform from March 2020 to March 2022. This adaptation was followed by additional manga series set in the same universe: To The Savior, illustrated by Akiko Kawano, which ran from June 2023 to December 2024, and a sequel series titled The Savior's Pride, which began serialization in March 2025. The original light novel series has continued publication, with twelve volumes released as of October 2025.

The work of Tenichi has also been adapted into an anime television series. Produced by OLM, the first season aired from July to September 2023, and a second season is scheduled to premiere in April 2026. This adaptation brought the story to a broader audience, maintaining the original narrative focus on a protagonist reincarnated into an otome game as a villainess destined for destruction who instead uses her knowledge and abilities to change her fate and protect those around her.