They filmed the scene in which a god enters Sungjae's body. Sungjae, who always is bright and cheery in the drama but suddenly turns sincere, stars to fly feet and fists at Gong Yoo. Lee Dong Wook holds Gong Yoo back, saying, "Why are you doing this to the kid? He did nothing wrong."
While filming this, the two engage in a physical fight. When Gong Yoo lifts both feet to do a high kick, he hit the back of his head against Lee Dong Wook's chin. Gong Yoo, taken aback, insisted, "I didn't intend to do that but Lee Dong Wook said from behind me, 'I'll hold you, so jump,'" making everyone laugh.
He then made sure Lee Dong Wook was fine, and Lee Dong Wook assured he was all right.