Late one night, Minhoon receives a call to come and pick up his extremely drunk childhood friend, Hyungwoo. The man reluctantly drags his friend back to his apartment to sober him up, only for Hyungwoo to suddenly kiss him and bite his lip in the process. Angrily demanding an explanation for Hyungwoo's actions, Minhoon is shocked when his friend admits that he is a vampire and that their fates are now bound together.

Though Minhoon hopes this confession will finally end the secrecy that has always shrouded their relationship, he realizes he is entering a completely different world as he learns more about vampires. While he does not understand much about Hyungwoo's kind, Minhoon will soon have no choice but to fight for the future of all vampires.

The Sweetest Man is originally a webtoon ebook series that was published in book format by Haksan Publishing. The series was published digitally in English by Tappytoon, Lezhin Comics, INKR, Tapas, Mangatoon, SideWalk Group through WebComics, and NHN comico Corp. through Pocket Comics. It has also been adapted into a Korean audio drama by AudioComics from July 31, 2020, to December 18, 2020.