Question: Which 2008 South Korean film based on the internet novel of the same name was written by Guiyeoni?

Context articles: Temptation of Wolves
Eighteen, Twenty-Nine
He Was Cool
Do Re Mi Fa So La Ti Do (film)
Scandal Makers
Death Bell
My Lovely Sam Soon
Portrait of a Beauty
Guiyeoni
Crossing (2008 film)

Temptation of Wolves (; also known as Romance of Their Own or True Romance) is a 2004 South Korean film directed by Kim Tae-kyun, and based on a novel of the same name by Internet author Guiyeoni.
 Starring Jo Han-sun, Kang Dong-won and Lee Chung-ah, the film is about an average high school girl who moves from the countryside to Seoul after her father's death only to become involved in a love triangle with the two most handsome and popular guys in town.
Eighteen, Twenty-Nine (; also known as 18 vs. 29) is a 2005 South Korean television series starring Park Sun-young and Ryu Soo-young.
 Based on the Internet novel "The 4321 Days We Shared", the romantic comedy series aired on KBS2 from March 7 to April 26, 2005 on Mondays and Tuesdays at 21:55 for 16 episodes.
He Was Cool (; lit.
 "That Guy was Cool") is a 2004 South Korean film based on the same-titled 2001 Internet novel written by Guiyeoni.
 The film was released in South Korean cinemas on July 23, 2004 and was the 35th most attended film of the year with 800,000 admissions.
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 (assistant director of "Romance of Their Own") and produced by New Crayon Entertainment.
 The film received 199,151 admissions nationwide.
Scandal Makers (; lit.
 Speedy Scandal) is a 2008 South Korean film written and directed by Kang Hyeong-cheol and starring Cha Tae-hyun in the lead role.
 This was director Kang's first film and the highest grossing Korean film of the year.
 A Chinese remake was released in 2016.
Death Bell () is a 2008 South Korean film.
 The only Korean horror film released over the summer of 2008, it is the first feature by former music video director Chang (real name Yoon Hong-seung), who also co-wrote the screenplay.
 "Death Bell" stars Lee Beom-soo in his first horror film role, and K-pop singer Nam Gyu-ri in her acting debut.
 Set in a Korean high school, the film's native title refers to "gosa", the important midterm exams that all students are required to sit.
My Lovely Sam-soon (; lit.
 My Name Is Kim Sam-soon) is a South Korean television series based on the internet novel of the same title by Ji Soo-hyun, which was published on March 9, 2004.
 Touted as the Korean version of "Bridget Jones's Diary", it starred Kim Sun-a (who gained 15 pounds for the role), Hyun Bin, Jung Ryeo-won and Daniel Henney.
 The series aired on MBC from June 1 to July 21, 2005 on Wednesdays and Thursdays at 21:55 for 16 episodes.
Portrait of a Beauty () is a 2008 South Korean film directed by Jeon Yun-su.
 Adapted from the bestselling novel "Painter of the Wind" () by Lee Jung-myung, the film portrays Joseon-era painter Shin Yun-bok (better known by his pen name, Hyewon) as being a woman disguised as a man.
Guiyeoni (born 1985) is the pen name of internet novelist Lee Yoon-sae.
 She first reached fame with her novels "He Was Cool" and "Romance of Their Own", 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", has become a film starring Jang Keun-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 called "Syndrome".
Crossing (also known as Keurosing) is a 2008 South Korean film directed by Kim Tae-kyun.
 It was selected as South Korea's submission to the 81st Academy Awards for Best Foreign Language Film.
 The film follows the journey of a North Korean man as he illegally leaves the country to find medicine for his sick wife, portraying the many hardships of the average North Korean citizen.
 The film had 907,255 admissions in South Korea.