The caption reads: "Happy birthday. I miss you so much. I'm always sorry to you and I will always love you." The picture shows Jonghyun sitting in front of a plate of tonkatsu.
Fans also commented, stating:
"I miss him too."
"Today is such a happy and sad day."
"I keep crying."
Key and Jonghyun began promoting together in 2008 when they both joined SHINee.