Guiyeoni is the penname of Internet novelist Lee Yoon-sae. She first reached fame with her novels He Was Cool

He Was Cool

He Was Cool is a South Korean film.-Plot summary:The film is based on a novel written by Guiyeoni. The story is about a cheerful high school student named Han Ye-Won . She is a sweet, clumsy and warm girl...

and Romance of Their Own

Romance of Their Own

Temptation of Wolves is a 2004 South Korean film directed by Kim Tae-gyun, and based on a novel of the same name by Internet author Guiyeoni...

, which spawned commercially successful films of the same name, as with another book, A Wolf's Attraction. Since then, one of her other books, Do Re Mi Fa So La Ti Do

Do Re Mi Fa So La Ti Do (film)

Do Re Mi Fa So La Ti Do is a 2008 South Korean film based on the internet novel of the same title by Guiyeoni. Directed by Kang Geon-hyang and produced by New Crayon Entertainment.-Synopsis:...

, has become a film starring Jang Geun Suk. A movie of To My Boyfriend is also in planning stages. Despite her commercial success, Guiyeoni has been criticized for her lack of literary perfection, overuse of emoticons, and unrealistic setting in her works. Besides the aforementioned novels, she has also written Africa, Five Stars, and written and illustrated a manhwa

Manhwa

Manhwa is the general Korean term for comics and print cartoons . Outside of Korea, the term usually refers specifically to South Korean comics. The term, along with manga, is a cognate of the Chinese manhua...

 called Syndrome.