On the recent episode of 'Radio Star', she revealed that she and Jang Geun Suk have been friends for 12 years. Not only that, but she shared that he is quite the amazing friend.

She shared, "We coincidentally met and people around us said 'You two are the same age, try it out' and it turned into a 'date' atmosphere. But we both didn't see each other in that way, and became friends from that point on."

She said, "There was a time I didn't have work and I was sullen, and he called me and asked me to sing at his Japanese concert tour. I was going to do it without receiving a performance fee, but Jang Geun Suk had secretly prepared my university tuition on the side. It's pretty much the same as him paying for my tuition."

SEE ALSO: Taemin explains why he was absent from SM's 30th anniversary concert

Now that's what you call a BFFL!