Two photos taken from the CF set were revealed of the two girls against a chromakey green screen posing with an automobile.
IU wore a plain white t-shirt while Yoo In Na wrapped a check-patterned shirt around her waist.
The two met on SBS 'Happy Sunday' back in 2010 and have been best friends ever since. Regardless of their 11-year age gap, both women presented a lively atmosphere on set.
Meanwhile, singer IU will be returning with a new single next month.