Yuin is a Korean novelist best known as the original creator of the web novel and anime franchise Surgeon Elise, also known as Doctor Elise: The Royal Lady with the Lamp. The person is credited as the sole author of the original story, which began as a Korean web novel serialized on the digital platform KakaoPage from December 2015 to April 2016.

Following the completion of the novel, the intellectual property expanded into a full media franchise. A webtoon, or Korean comic adaptation, illustrated by the artist mini was serialized on the same KakaoPage platform from September 2017 to February 2021. Yuin is consistently credited as the original author and source material creator for this adaptation. The franchise culminated in an anime television adaptation. The anime series, titled Gekai Elise, was produced by the animation studio MAHO FILM and aired for a full season of twelve episodes from January to March 2024. For the anime production, Yuin is officially credited as the original creator.

The story central to Yuin's work follows the protagonist Elise, a reincarnated former empress who uses medical knowledge from a past life as a modern surgeon to change her fate in a fantasy imperial setting. This narrative blends the genres of isekai, or other world reincarnation, with medical drama and romance. The central theme involves atonement and the application of advanced, real-world scientific knowledge within a less technologically developed fantasy society.

The significance of Yuin's work lies in its successful trajectory from a Korean web novel to a Japanese anime production, a path that highlights the increasing globalization of East Asian popular media. The Surgeon Elise anime stands as a direct adaptation of Yuin's original narrative and serves as the primary point of reference for the creator's profile in the Japanese and international anime market.