A dark and handsome stranger appears on You Jin's doorstep one day, claiming to be a childhood friend that's contracted a mysterious and potentially fatal disease—the reason You Jin doesn't recognize him. Being the long-lost childhood friend that he is, he asks You Jin to help fulfill his dying wish. But can You Jin trust this beautiful stranger? (Source: Lezhin Entertainment)

You Jin began as a web comic released on the author's blog, and was serialized on Lezhin Comics from July 6, 2016 to December 26, 2016. It was also published as donginji in 3 volume and 2 volume editions. The series moved to Ridibooks on March 15, 2021, where 5 new full-color side stories were published. The original 2016 release of the series was published digitally in English by Lezhin Entertainment from March 1, 2017 to May 25, 2017.