Why are K-drama stars Ahn Jae-hyun and Koo Hye-sun getting a divorce?

HB Entertainment, Koo and Ahn’s management agency, say they are proceeding with the divorce by mutual agreement
South Korean actress Koo Hye-sun has revealed that she and actor Ahn Jae-hyun are divorcing after three years of marriage.
“I want to stay together, while my husband who has reached a stage of ennui, wants [a] divorce,” Koo, 35, wrote in an Instagram post on Sunday, alongside a photograph showing a handwritten note from her husband saying: “I love you, Koo Hye-sun.”
Koo added: “I should let you know the press release from my husband, which will be disclosed [this] week, is not true.”
She said she had posted her comments on Instagram because her mother had been shocked by the news.
Koo also uploaded screenshots of the couple’s text message conversation, in which Ahn wrote: “I have already talked to the New Journey to the West [reality television show] team and said I will submit the agreement and other paperwork next week that you gave me three days ago.”
Koo asked Ahn to personally meet her mother and persuade her to accept the divorce, as he had done for their marriage.
However, Ahn said he would not “know what to say in person” if he met Koo’s mother, and would talk to her on the phone.
I want to stay together, while my husband who has reached a stage of ennui, wants [a] divorce
Koo said she would not stay if he did not apologise to her mother, and the text conversation ended there.
New Journey to the West is a Korean travel series where Ahn is a regular panellist.