
Jo Kwon and Wooyoung have indeed been known as K-Pop idols who have been close friends for years, as they both became trainees at JYP Entertainment.
Wooyoung is known have completed his mandatory military duty in February, while Jo Kwon has just completed his mandatory military duty today, March 24, 2020.
Likewise with Song Mino and P.O who have been close friends since high school. The two have also often starred in variety show programs together, including 'New Journey to the West', 'Kang's Kitchen' and 'Mapo Hipster'.
The episode of 'Knowing Brother', starring the four, will air on April 4th, 2020. (www.onkpop.com)