Lee Min Jung, having not slept for 3 days, is having a "mental breakdown", according to Gong Yoo.

In a "making-of" video clip posted on the official website for the KBS2 Monday-Tuesday drama 'Big', shows the filming of a reunion scene between Kang Kyung Joon (played by Gong Yoo) and Gil Da Ran (Lee Min Jung) at a wedding hall.

Gong Yoo and Lee Min Jung set a friendly atmosphere around the set, constantly smiling and laughing. Gong Yoo in particular led the pleasant effort, cheering up a tired, sleepless Lee Min Jung and holding her arm unreservedly.

When Lee Min Jung began walking around mumbling, Gong Yoo clapped behind her and explained, "Mental breakdown. She didn't sleep. For three days." Despite being unlikely to have slept either, Gong Yoo warmly took up the responsibility of cheering up Lee Min Jung and the crew as well.

'Big' is gaining positive attention and reviews, in part due to Gong Yoo's ability to play the role of two complete opposite characters, Seo Yoon Jae and Kang Kyung Joon.