In the winter of 1598, the seven-year Imjin War nears an end as the Japanese Wae invaders prepare to withdraw from Joseon. Admiral Yi Sun-shin leads an allied fleet of Joseon and Ming ships to annihilate the Wae army. Joseon, Ming, and Wae forces clash at Noryang Strait, the deadly sea where Admiral Yi fights his last valiant battle.

After a high-ranking North Korean official requests asylum, KCIA Foreign Unit chief Park Pyong-ho and Domestic Unit chief Kim Jung-do are tasked with uncovering a North Korean spy, known as Donglim, who is deeply embedded within their agency. When the spy begins leaking top secret intel that could jeopardize national security, the two units are each assigned to investigate each other.

A woman who appears like fate, I will protect her till the end! 'Soo-han' who lost both her loved one and the motivation to live, works at a private loan company with her colleagues, 'Tae-yeong' and 'Jin-cheol'. Then one day, 'Soo-han' helps 'Ye-jin', who was being chased by gangsters, by hiding her in the house. Actually, 'Ye-jin' is the only successor of 'Taejin Group', and is being chased by 'Cheol-woong' who wants to take over the group. Meanwhile, CEO Cho, the CEO of the private load company, starts looking for 'Yejin' at the request of 'Cheolwoong', and soon learns that 'Suhan' and 'Yejin' were related ...

When the investigation of 'Koreagate' takes place, Park Yong-gak, a former KCIA director who knows everything about the government's operations, heads to the United States in exile.

Beautiful, workaholic Bo-hee is a successful marketing executive at the number one toy company in Korea. Respected by her colleagues and in line for a promotion, she makes an irrevocable mistake that gets her fired from her job. Bo-hee's life further spins out of control when her husband Gang-sung leaves her soon after. Bo-hee is befriended by her neighbor Nan-hee, an amateur sex expert who runs a sex shop on the brink of bankruptcy called "Casa Amor." Nan-hee's predicament inspires Bo-hee's creativity, and using her background in children's toys, she is determined to save the shop by making its ambiance more refined and by promoting better sex toys.

Two spies share a secret bond, despite their loyalties. A North Korean assassin is sent to Seoul to kill a dissident, but instead he teams up with a South Korean agent in search for revenge.