AOA's Mina was spotted in tears during a hidden camera prank prepared for ChoA, who celebrated her birthday on March 6 on the recent broadcast of N.Flying's reality show "Cheongdamdong 111 - N.Flying's Way to Be a Star".

AOA came up with a secret plan to get ChoA out of the dorm so that the members can set up a surprise birthday celebration by getting Mina to feign sickness for their hidden camera prank. Mina's acting was so good that ChoA really believed her, spilling tears during a game and got ChoA to escort her outside without a question. Once ChoA came back, she was surprised by her group who up a wonderful birthday celebration just for her.

Watch the girls on how they score a one day vacation from their busy schedule along with their hidden camera prank on the second episode of "Cheongdamdong 111 - N.Flying's Way to Be a Star".