From all appearances, Lee Jong Suk is a pretty friendly guy. But his friendships have a way of starting rumors.

He is said to be a good friend to have. His closest friend Kim Woo Bin describes him as sensitive.

"He's warm, caring and compassionate," said Kim, who starred with him in "School 2013" and has snagged a role in "The Heirs."

But the mind-reading star of "I Hear Your Voice" can also be unpredictable, which makes him a fun friend to have. The two are so close their friendship has been described as a bromance and fans even wondered if they were dating.

Lee Jong Suk's friendship with f(x) member Krystal Jung also provoked comments. When Lee Jong Suk said he missed Krystal and liked her on two different variety shows, everyone assumed they were romantically involved. He had to clarify his statement on a subsequent show, saying they did not have a special relationship. When she was asked about their friendship, she could only say they stay in touch.

Then there was the rumor that he and IU, star of "You're The Best Lee Soon Shin," were enemies. And while he did get annoyed at her costume ideas while they were emcees on "Inkigayo," he kept quiet about it. When IU learned about this issue, she apologized.

"Jong Suk oppa never said anything to me when we were working together, so I had no idea he felt that way," said IU. "After I watched that episode, I realized he must really not have liked the costume, so I apologized to him."

The two are good friends today and often call each other.

And now the buzz is about Lee Jong Suk and Girls' Generation's Yuri. The two co-star in the swimming film "No Breathing." She posted a picture of them on Instagram. They are standing close together and she is poking his cheek. She says "I met Park Soo Ha while filming 'No Breathing.' Did you read my mind too?"

She refers to his character Park Soo Ha in "I Hear Your Voice," a young man who can hear other people's thoughts. But netizens already wonder if they are dating.

Earlier this year he denied rumors that he was dating actress Jung So Min of "Playful Kiss" and "Bad Guy" because they were in Japan at the same time and ran into each other at the airport. The two once shot a commercial together.

Lee Jong Suk can't help being friendly and charming. And he's so popular that anyone he spends time with can't avoid being talked about.