Park Kahi~ lived in the United States. She is warm and nice to people she knows, but yet she is cold and in a way mysterious to those who don't know her well. She is stubborn and independent. Live with her parents in the US for 10 years. 

Kim Uee~ been best friends with Kahi for 6 years. Carefree and fun. Alot more understanding and reasonable than Kahi. Also very independent. Moved away with her father when her parents split when she was 16. Now 25 years ol

Min Sunye~ Lived in the Hong Kong. She's Uee's younger sister. Stayed in Hong Kong with her mother. Kept in touch with Uee all these years. Nice and caring, a bit stubborn in here own way.

Kim Jaejoong~ police. Best friends with Yunho and Jiyong. Has a high ranking in the police force. Is someone who doesn't talk much and serious about the job. Doesn't trust any girl because he had his heart broken by his girlfriend of 5 years.

Kwon Jiyong~ . Funny and smart. He's a bit lazy but very skilled at what he does. He and Yunho are one notch below Jaejoong in the Police force. Likes to joke around and talk.

Jung Yunho~  Quick and fast. He's a good police. He talks alot and is stubborn. Smart and intelligent too. Skilled at everything he does. A basic know it all.

Everyone but Annie and Ada lives in Hong Kong. Charmaine is also a police in the same Department as Sunny, Louis and Chilam. She's good friends with them.