Hip hop group Dynamic Duo revealed their concert practice with singer Park Jung Hyun.

On December 10, Gaeko posted on his Instagram, "'That Year, Winter's Collaboration" along with a picture.

In the picture, the three are sitting in the practice room, in front of their own mics. Gaeko is pretending to eat his mic and Park Jung Hyun is laughing at him, Choiza making a shocked face.

Internet users who saw this commented, "Choiza's face says, 'What is he doing?'," "I love Dynamic Duo," and "I can't wait."

Dynamic Duo and Park Jung Hyun will be holding their collaboration concert "That Year, Winter" from December 20 to 27.