Lee Hye-young is as busy as a bee in spring.
Apart from her primary job as an actress, she attends business meetings, settles accounts and appears on home-shopping television channels to promote fashion products.
Lee, 37, launched her own fashion brand, Missing Dorothy, in 2004 because of her interest in fashion.
The line reached 40 billion won ($42.3 million) in sales last year.
Lee is just one of many celebrities who have a side job.
Numberous well-known actors have their own fashion labels, including Uhm Jung-hwa "Zuhm in New York", Hwang Sin-hye "Elypry", Byeon Jeong-soo "Ella Hoya Secret", Hyeon Yeong "Vivacella", So Yoo-jin "Silver Apple" and Chae Yeon "Cycloset".
"Professionally, entertainers have lots of contact with the fashion industry", said Baek Eun-sook, a public relations official of Missing Dorothy.
Lee first launched a clothing line in 2004 and it quickly became popular.
She launched a lingerie brand with the same name in 2007.
That year, Missing Dorothy merged with M Corset, a professional lingerie company that owns the firms Lefee and Kiss Republic.
Now, Lee is the director of M Corset.
"Lee is more than just a brand- name model", Baek said. "She takes thorough charge of the brand by product planning, designing, marketing and promoting".
With the growing number of celebrity labels, home-shopping channels are grabbing a big chunk of the profit.
Hyundai Home Shopping, for example, raised 2 billion won in a four-month period after it broadcast eight promotional episodes for Ella Hoya, a lingerie label started by actress Byeon.
A set of Ella Hoya lingerie costs 169,000 won.
The home-shopping channel also sought to make some money by selling Elypry lingerie, launched by Hwang.
The brand earned 12 billion won last year.
Hyundai Home Shopping also launched actor Lee Hyeon-woo's menswear line Lawren & Miles and Jeong Seon-hee's makeup label, Senerine.
"There are lots of benefits to launching a celebrity brand on home-shopping channels", said Oh Hyung-joo, a marketing manager at Hyundai Home Shopping.
"They [celebrities] have high name-recognition, which makes it easy for them to promote products to customers".
According to Oh, star-labeled brands make 130 percent more profit than other general brands.
They also have 3 to 5 percent fewer customers asking for a refund.
Star-labeled products aren't only limited to the fashion industry.
Increasingly, entertainers are putting their names on restaurants, street snack stalls and even fitness centers.
Television actress Jo Eun-sook is one of them.
In 2004, she opened a 40-square-meter hot dog place (Barun Saenghwal Hotdogs) near Hongik University.
She invested 35 million won and now regularly earns an average of 6 million won a month.
Television actor Hong Seok-chun also owns Our Place, a restaurant in Itaewon, central Seoul.
He personally visits the market three times a week for ingredients.
Hallyu, or Korean wave, actor Bae Yong-joon owns Gorilla in the Kitchen, a restaurant near Dosan Park in Sinsa-dong, southern Seoul. It is a well-being restaurant.
All of the menu items were co-created by a chef, nutritionist and a fitness trainer.
The restaurant is a tourist attraction to many of Bae's Japanese fans.
Comedian Bae Yeon-joon is a veteran at running a business on the side.
With three years of experience managing a beauty salon in Itaewon, she opened her own Korean restaurant in Gonjiam, Gyeonggi, in 1998.
Now, she has branches in Cheongpyeong and Byeokje in Gyeonggi, and Singil-dong in northern Seoul.
Other star-owned restaurants are Lin Chin, owned by the couple Kim Hak-rae and Lim Mi-sook; Kim Jong-min's Eoribeori; Yoon Jeong-soo's Cheongdaman; and Tak Jae-hoon's Nabigung; all in southern Seoul.
Why such a boom in side jobs?
"Unless you are a top star with millions of won in advertising contracts, entertainers suffer from irregular incomes", said Kim Han-kil, a star marketer.
"They [entertainers] seek a stable living amid the unstable entertainment business, and one way to do so is to have side jobs".
Kim said a star's reputation tends not to last long.
Lee Myung-ok, a professor at Samsung Art & Design Institute, predicts that more stars will establish their own brands and open restaurants.
She's optimistic about the trend.
"People tend to follow what celebrities do", Lee said. "Star fashion brands, in particular, will get plenty of the spotlight in the future, creating more fashion choices for consumers".
Park Ji-eun, a dance sports player, is worried that star-labeled businesses will become too commercialized.
Park, who opened her own online shopping mall this month, said, "With entertainers advertising their own labels, their business can be a personal publicity tool".