P4: are the new recruits in the violent crimes unit at Gangnam Police Station. The journey of four young cops as they fumble, learn, fall in love and find their way to becoming people the ci... Read allP4: are the new recruits in the violent crimes unit at Gangnam Police Station. The journey of four young cops as they fumble, learn, fall in love and find their way to becoming people the citizens can trust.P4: are the new recruits in the violent crimes unit at Gangnam Police Station. The journey of four young cops as they fumble, learn, fall in love and find their way to becoming people the citizens can trust.