Demon Diary (ko: 마왕일기 mawang ilgi, "Diary of a Demon King") is a 7-volume soonjung Japanese style manhwa (Korean comic) illustrated by Kara.

"Kara" is the name of the duo team consisting of Kim Yoon-gyeong and Jeong Eun-sook.

Demon Diary was originally published by Sigongsa and has been licensed in North America by Tokyopop.

A number of writers have worked with Kara on the production of Demon Diary.

Lee stopped writing, because he had to prepare for the upcoming high school exams.