A woman in her late 20's is always asked "when are you going to get married?" On a whim, the woman then lies that she did get married.
Kong Ah-Jung (Yoon Eun-Hye) is an administrative official for the Ministry of Culture, Sports and Tourism. She then co-ordinates a meeting for government officials. The meeting appears to flow smoothly and she is even praised by the minister. Disaster soon strikes when bees attack the meeting place and the meeting turns into chaos. Taking responsibility for meeting, Ah-Jung is ordered to submit a written apology. That evening Kong Ah-Jung goes to a club and drinks away her sorrows.
Meanwhile, Hyun Ki-Joon (Kang Ji-Hwan) is the president for conglomerate "World Group." He is handsome, smart and from a rich family. But, in his teen years due to an accident he lost both of his parents. Since that time, Ki-Joon and his younger brother were raised by his aunt. Ki-Joon has a responsible character as an older brother but his younger brother Sang-Hee (Sung Joon) is more carefree. The younger brother Sang-Hee then comes back to Korea and meets Ah-Jung at the club, while she is drinking away her sorrows. Ah-Jung and Sang-Hee start to chat and Ki-Joon shows up to looking for Sang-Hee. He misses Sang-Hee. in front of the club Ah-Jung passes out and Ki-Joon takes her to the hospital. In order to ask Ah-Jung about Sang-Hee's whereabouts, Ki-Joon stays next to Ah-Jung's bed all through the night. The next day, they go their separate ways.
On the following day, Ah-Jung meets So-Ran (Hong Soo-Hyun) who stole away her first love Jae-Beom (Ryu Seung-Soo). So-Ran and Jae-Beom eventually married. After So-Ran and Jae-Beom became a couple, Ah-Jung studied hard and passed her government official exam to impress Jae-Beom. At the hair salon, Ah-Jung on a whim lies to the couple and tells them that she is married. Ah-Jung then goes to a hotel to pay Ki-Joon for the other night's hospital bill. An accident occurs and she spills tomato juice all over her sweater. Ah-Jung is so embarrassed she pretends to pass out. Ki-Joon picks her up and takes her to his hotel room. During this time, Ah-Jung's friends watches and a rumor soon spreads that Ah-Jung and Ki-Joon are married ....
Source from: http://asianmediawiki.com/Lie_to_Me_(Korean_Drama)