The cast members in attendance included lead actor Lee Sun Gyun, lead actress IU, Oh Dal Soo, Song Sae Byuk, Lee Ji Ah, Jang Ki Yong, Shin Goo, and more. 

Lee Sun Gyun, Oh Dal Soo, and Song Sae Byuk will be banding together to greet viewers with their 'ahjusshi three musketeers' chemistry on 'My Mister'. Opposite the trio, IU will be playing the role of a cold and rugged city girl who struggles to get by every day. The four will come together despite their different lifestyles and provide healing for one another. 

You can catch their unlikely story on 'My Mister' beginning March 21 at 9:30 PM KST, and their newest, short teaser, above.