Sandra Oh leaving 'Grey's Anatomy'

ABC's top-rated drama "Grey's Anatomy" will lose one of its original and best-loved stars, Sandra Oh, who has played doctor Cristina Yang since the series premiered in 2005.

"Creatively, I really feel like I gave it my all, and I feel ready to let her go," Oh said. "[Cristina] wants to be let go, and I am ready to let her go. We have to start the process, story-wise, for the Grey's writers to think of why she's going to go."

Oh, along with the rest of the "original six" cast members signed new two-year deals in 2012 that would carry them through the tenth season.

"I've gone through a lot of therapy over this," an emotional Oh said. "I started thinking about it because I had to prepare myself. I gave myself two years to emotionally let go. At the end of last season, Shonda took me aside and said, 'What are your thoughts?' I said, 'I'm ready.'"

Series creator and showrunner Shonda Rhimes says Yang was the second character she created, after Meredith Grey. A driven doctor who puts her career above her personal life, Rhimes says she considers herself similar to Yang.

"One of the best days of my life as a writer happened the day Sandra Oh walked in my door to audition and forever changed the course of Grey's Anatomy with her brilliant, nuanced portrayal of Cristina Yang," Rhimes said.

"This year is going to be bittersweet for us," said Rhimes. "We're both going to savor every moment of Cristina Yang, and then we're going to give her the exit she deserves."