Unlike most first script readings which usually have a more serious and awkward atmosphere as they're usually the first time that the leading cast and staff all come together, those starring in tvN's 'Flower Grandpas Investigation Unit' started off the filming with laughs and jokes.

SEE ALSO: Heechul to star in the drama version of 'Grandpas Over Flowers'

Lee Soon Jae, Byun Hee Bong, Jang Kwang, Lee Cho Hee, Park Eun Ji, and Super Junior's Heechul were full of laughs during the script reading for episodes one and two at CJ E&M Center in Sangamdong, Seoul. Although he apologized and was shy at first, Heechul worked up the guts to talk to veteran actor Lee Soon Jae using informal speech for his role, adding to the comical nature.

'Flower Grandpas Investigation Unit' is directed by Kim Jin Young and written by Moon Sun Hee and is a comic drama of young detectives who transform into their 70-year-old selves one day and struggle to find a way to return to their twenties.

The drama will premiere following the conclusion of the variety show it got its inspiration from, 'Grandpas Over Flowers', on May 2 at 9:50 PM KST!