MAMAMOO revealed why they were totally surprised by Lovelyz' Kei on Mnet's 'Queendom'.

On the October 10th episode, the MAMAMOO members talked about Hwa Sa and Kei's collaboration unit, and they all revealed they were surprised to hear the two singers were the same age. Solar stated, "In terms of her appearance, she's like a baby and very cute, but her voice wasn't like that. It was very mature. It surprised me a bit. Unexpected."

Hwa Sa added, "It seems like she'd be really shy, but she actually knew how to lead me. She was very assertive when she approached me." MAMAMOO also expressed how they were looking forward to the collaboration as Hwa Sa and Kei have completely different images.

Check out the clip above!