Three brothers Bin, Hyun and Joon become drawn to the very pretty and sweet Yuri, a family friend. Yuri arrives from France to live with them for the summer while attending classes at their university, causing each brother to be attracted to her in a different way.

Two friends, Lee Dong Min and Yoon Chul Joon, grow apart and then became bitter rivals as while playing for competing university basketball teams.

Trio tells the story about 3 boys who befriend each other and become known as the Trio of Incheon. The drama is about the bond of friendship between 3 guys who grew up together. Their friendship endures, even though they may face obstacles and hardships between them. Trio is one of the feel good dramas after you watch it. The drama makes you want to cherish the friendship you have in your own life.