After his mother is brutally murdered in front of him by the Thai criminal syndicate Cheongbang, Suhyeon (Lee Junki) is adopted into NIS agent Jungho’s family. Together with Mingi (Jung Kyungho), Jungho’s son, Suhyeon becomes an NIS agent. Suhyeon met Jiwu (Nam Sangmi) when they were about 12 years old and has another fateful encounter with her 13 years later. Together they had promises for the future. One day, Suhyeon leaves for an operation dealing with the Cheongbang, only to return in failure because of the resurfacing terrible childhood memories of when he was in Thailand. The chief of NIS agents, Jeong, proposes to the distraught Suhyeon to infiltrate the Cheongbang. Through Chief Jeong’s proposition, Suhyeon becomes an undercover NIS agent after staging his death. Hiding his past, Suhyeon infiltrates the Cheongbang with revenge in mind, leaving Jiwu behind. Under the pseudo-name of Kay, he passes through the backstreets of Bangkok. What Suhyeon didn't know Jiwu is the daughter of the same villain. Meanwhile Mingi has fallen in love with Jiwu source: http://en.wikipedia.org/wiki/Time_Between_Dog_And_Wolf
