SEE ALSO: Choo Sarang, Dae Han, Min Guk, and Man Se go on another play date for 'Superman is Back'

Choo Sung Hoon, Choo Sarang, and Yuto visited a fire station where the children put on miniature fire helmets and uniforms to experience what it's like to be a firefighter. But when it was time to put their skills to the test, Choo Sarang surprised those on set with her ability to stop a fire with the hose. Upon seeing this, Choo Sung Hoon couldn't hide his fatherly smile as he told her, "Aigoo~ You're doing well."

Stay tuned for their adorable transformation this Sunday at 4:50 PM KST!