When actors Jo In Sung and Go Hyun Jung were seen together at an airport in Japan, rumors started flying. Were the two in a relationship?

Not so, says IOK Company, the agency that represents them both. It was just a coincidence.

"They went to Japan on different schedules but they happened to return at the same time when they finished work," agency representatives told the Korean media outlet Nate TV. "They definitely don't have the kind of relationship one would suspect by looking at the picture. They coincidentally returned at the same time together."

The actors have been friends for 10 years, since they both starred in the 2005 drama "Spring Days." The drama, in which they played lovers, was very popular, earning 30 percent in viewer ratings.

Go Hyun Jung has spoken about their friendship on various TV and radio shows. In 2008, she was complimenting him on the MBC radio show "Park Kyung Lim's Starry Night" and confessed that she expresses her feelings for him.

"I sometimes jokingly tell him that I love him and ask him to marry me," she said on the program.

She also said she wanted to date actor Chun Jung Myung but wanted "to marry Jo In Sung." He was the first guest on her SBS talk show the "Go Hyun Jung Show" and they met up for tea before he joined the military.

So, if the actress and former Miss Korea runner-up were really dating Jo In Sung, she would probably be frank about it.

Go Hyun Jung appeared in "Sandglass," one of the highest-rated and most critically acclaimed dramas in Korean TV history. She also enjoyed success as a result of her 2009 drama "Queen Seonduk" and the 2010 drama "Daemul." She retired from acting in 1995 when she married a chaebol named Chun Yong Jin but divorced him in 2003. Her most recent drama was "The Queen's Classroom" in 2013. In 2014 she began teaching acting as an adjunct professor at her alma mater Dongguk University.

Jo In Sung recently enjoyed success with the dramas "It's Okay That's Love" with co-star Gong Hyo Jin and "That Winter The Wind Blows" with Song Hye Kyo. Jo In Sung dated actress Kim Min Hee for over a year but broke up around the time he was filming "It's Okay That's Love." At that time he was rumored to be seeing his co-star Gong Hyo Jin, who also broke up with her boyfriend Lee Jin Wook. Both actors denied the rumors.

Both actors are currently considering future projects.