Season 1 Blue Tower tvN , 2013 An army background story about a group of guys in the army. Season 2 Blue Tower ZERO tvN , 2013 Prequel of the original 'Blue Tower'. It talks about when Choi Jong Hoon first entered army at the boot camp. Season 3 Blue Tower Returns tvN , 2013 - 2014 This new season will focus on the last year sergeant squad in the army.