Another South Korean star Cha In-ha was found dead at his home.
Cha made his film debut in 2017, and was previously a member of boy band Surprise U.
The 27-year-old actor is the third young celebrity in South Korea to die in the past two months.
It casts a dark cloud over the country's lucrative entertainment industry, and drives debate about the intense social pressure artists have to face.
On Wednesday (December 4) fans mourned his death: (SOUNDBITE) (Korean) 27-YEAR-OLD SOUTH KOREAN RESIDENT, KIM DAE-HAN, SAYING: "He was my age, which made me sadder.
I think they might be in pain even though their life looks very fancy.
There can be many cases in which the parents want their children to become an entertainer or they want to be one themselves, but I hope management companies will take responsibility for them and arrange more professional counselors for regular counseling." Cha's talent agency Fantagio put out a statement mourning the loss of the star.
It comes after K-pop singers Sulli and Koo Hara were also found dead this year.
The industry has also been hit by a series of sex scandals, with two K-pop band members sentenced to prison for sexual crime.