Nicknamed the nation's little brother and sister, IU and Lee Hyun Woo would undoubtedly make an adorable couple. The friends have even appeared in several couple photo shoots in magazines. But they are undoubtedly just friends.

Dating rumors surfaced after paparazzi captured IU and Lee Hyun Woo walking out of a movie together. When asked about the truth behind the rumors on "Night of TV Entertainment," IU burst out laughing, so much that Lee Hyun Woo almost seemed insulted, blurting out, "Why are you laughing so hard?"

Lee Hyun Woo and IU first met on the set of the Korean music program "Inkigayo" and naturally became good friends as they co-hosted the show. Lee Hyun Woo was since featured in IU's music video for "You and I." The friends apparently had a hug scene in the music video that was ultimately killed because they looked too awkward. They may be close, but perhaps they are better off staying friends!

Yoo Ah In has stated publicly in the past that Jung Yoo Mi is his ideal type, but the two have since become the best of friends. As displayed on social media, they celebrate each other's birthdays, attend the social gatherings and share the same friends. They also attend red carpets and public events together -- in 2015, Jung Yoo Mi was captured sending hearts to her best friend at a fashion show.

The two actors met while filming the 2007 film "Skeletons in the Closet." Yoo Ah In said he fell for her natural, genuine charm. Six years later, they appeared together as lovers in the film "Tough as Iron." On filming their kiss scene, Yoo Ah In and Jung Yoo Mi said they were able to film it professionally without any awkwardness because of their close friendship. For the drama "Discovery of Love," it was also revealed that Jung Yoo Mi -- a protagonist in the series -- was the reason behind Yoo Ah In's cameo appearance.

It's clear Jung Yoo Mi and Yoo Ah In's friendship has no bounds, whether on or off the camera!

The two melted hearts as a couple in "Reply 1988." But it turns out they were actually really good friends long before the series. Both film majors, Ko Kyung Pyo was Ryu Hae Young's senior at Konkuk University. Ryu revealed that instead of being timid, she approached Ko Kyung Pyo first and spoke informally to him, sparking their friendship.

They say when two people are in love, they start looking like each other. But these friends are so close they've even been mistaken to be twins in real life!

An apology to all you "Reply 1998" fans, but these two are most likely to remain friends. In an interview with Cosmopolitan magazine in 2015, Kyo revealed that he had told Ryu, "If we date because we grow feelings for each other and break up, we won't be bale to see each other for a longtime, so let's just remain friends for a long time."

If you didn't know them, you could easily mistake these two to be siblings because of their similar facial features. The two became friends after appearing together as a newlywed couple in the 2013 drama "Pots of Gold." Their performance even earned them a nomination for the best couple at a drama award show.

The two have also appeared together in the music video of The One's song "One, Two, Three, Four" in 2014.The singer shared that he feared his song might be shadowed by Baek and Seo's cameos because the two looked so good together.

Baek Jin Hee and Seo Joon have not been shy to display their friendship in public. They're been wrapped in dating rumors several times because of the number of intimate selfies they've taken and posted on social media. They've even posted photos wearing the same striped t-shirt and puff jacket, as well as a ring of similar design that could totally pass as a couple ring.

These two are well known for starring together in the 2009 drama "You're Beautiful." After their appearance on the drama, the two had even emerged as the number one couple netizens wished were dating in real life. But the actors actually first met on the set of a makeup commercial.

Speaking on the program "Taxi," Park Shin Hye revealed that Jang Geun Suk's mother had even expressed her desire to have her as a daughter-in-law. While Park is younger in age, Jang Geun Suk has said that she feels more like an older sister.

But Jang Geun Suk is just one of Park Shin Hye's many male-person-friends that she met on set. She is also known to be good friends with "You're Beautiful" co-star Jung Yong Hwa, Lee Jong Suk of "Pinocchio," Lee Min Ho of "The Heirs," among many others. This probably attests to her great personality!

Shinji and Kim Jong Min have displayed their perfect harmony for more than a decade, literally as members of the hit K-pop group "Koyote" and also as good friends.

Kim Jong Min was there for Shinji during times of hardship. Shinji revealed that she had suffered from stage phobia and locked herself in her house for three years. Shinji said during that time, Kim Jong Min was the only person who checked up on her regularly. Kim Jong Mi felt Shinji was struggling because of the pressures she had endured protecting Koyote as a group throughout the years. "I'll protect the group now, so you can get some rest," he told her.

Appearing together on an episode of "1 Night 2 Days," Kim Jong Min said despite her tough, ssen-unnie image, Shinji is actually soft-hearted." But these two never let things get sappy. He immediately sparked laughter when he joked that the reason he does not introduce men to Shinji is because, "he doesn't want to feel sorry for them afterwards."

Henry and Amber gave a very raw look at their humorous friendship on the show "I Live Alone." As a featured guest on several episodes, Henry has invited Amber to his house as well as randomly called her numerous times on Facetime. On one episode, the friends even engage in an "ugly battle" war on Facetime, seeing who can make the funniest faces.

As they are both living in South Korea, miles away from their families -- Amber is from Los Angeles and Henry is from Canada -- the two are seemingly very understanding and supportive of each other.

Kim Hee Chul is known to have many female friends, but Tae Yeon is one of his closest. They've displayed their friendship on their social media accounts, as well as on air. Kim Hee Chul has described Tae Yeon as a "little sister I love very much."

On an episode of the reality program "The TaeTiSeo," Tae Yeon expressed her gratitude for Kim Hee Chul, saying that aside from her Girls Generation members, she has no close friends but connects very well with Kim.

Lee Sung Kyung was revealed not too long ago to be in a relationship with her "Weightlifting Fairy Kim Bok Joo" co-star and labelmate Nam Joo Hyuk. But before that, she was speculated to be dating Zico.

During one interview, the model-turned-actress said that she was "exhausted" by the dating rumors involving her and her male friends, so much that they've caused her to spend more time indoors. And when she does leave, it's never without her baseball cap.

She also clarified one of the photos that sparked the dating rumors, where she and the rapper appear to be eating together at a restaurant. Lee Sung Kyung explained that their other friends were also present, but that they had been cropped out of the photo.

On an appearance on the program "Taxi," Zico sparked laughter by sharing that he was almost insulted by Lee Sung Kyung's strong denial of dating him and not seeing him as a man.

Park Na Rae got to live her "dream" of marrying comedian Yang Se Chan on a New Year's special of "We Got Married." Park Na Rae has revealed several times on air that she has had a crush on Yang. Should this dream ever become a reality, it would mean Park Na Rae would become the sister-in-law of one of her dearest friends, comedian Yang Se Hyung!

When Yang Se Hyung had trouble coming up with the down payment for his new home, Park Na Rae reportedly lent him $1 million. Money cannot buy friendship, but it's evident that Yang and Park have a very trusting relationship.

On an episode of "Radio Star," Park Na Rae urged Yang Se Hyung to help her get together with his little brother. The set broke out in laughter when he replied, "If you and your brother date and get married, I will voluntarily leave this world."