Kim Jong Kook took to Instagram to pen a heartfelt post, thanking his fans as he reaches 1 million subscribers on YouTube. 

Fans who have been following the singer will know that he is well-known for his witty hashtags. This time, it was no different. He took the opportunity to hilariously tease his fans and ask them, "where have you guys been hiding?" whilst also bashfully thanking everyone and promising to work hard, so as not to let his fans down. 

Check out his recent video that has already garnered more than 6.7 million views.