"Are you ready?" Ahn Yoo Na squinted at Lee Do Hwa who was casually wearing his shirt.
"Of course!" replied Lee Do Hwa, smiling at Ahn Yoo Na.
"Remember! Our mission is not to be uncovered before we get to the ship! " said Ahn Yoo Na.
"Are you doubting me Ahn Yoo Na? Besides I am the former idol group members, I can also act well, "said Lee Do Hwa as he pursed his lips to hear Ahn Yoo Na, who seemed unsure about carrying out her secret mission with Lee Do Hwa.
"I know you're a superstar, so you don't need to talk about your old profession again!" Yoo Na protested with a cynical face.
"Yoo Na, don't you call me with your outrageous. Why don't you call me Oppa? I'm older than you!" said Lee Do Hwa objected because Yoo Na did not call him Oppa. Call a woman to an older man.
"I'm not used to calling you Oppa," Yoo Na replied indifferently. She went back to stuffing her secret mission kit into her suitcase and also to some of her make-up places.
"So, there are people who will suspect us if you only call me just with a name. Why don't you call me Oppa, Yeobo, or Jaggiya? " Lee Do Hwa mentioned some special calls for a couple.
"I won't. I'm not accustomed to." Yoo Na is stubborn.
Lee Do Hwa could only snort in annoyance. If only it wasn't for the sake of their secret mission. Lee Do Hwa also doesn't want to have anything to do with Ahn Yoo Na.
Due to a misunderstanding, Lee Do Hwa had to end up marrying Ahn Yoo Na to carry out a secret mission. Ahn Yoo Na was one of the NSS secret agents who was investigating Julian Park's death. A case that was never resolved in the last three years. Meanwhile, Lee Do Hwa was a former member of the idol group Seven-F who runs a travel business.
To find clues to Julian Park's death case. They got married so they could enter Ferry Park's Guardian Ship. Guardian Ship created an event that only celebrity couples could participate in. For this reason, the leader of the NSS agent team Lee Jun Ki asked Ahn Yoo Na and Lee Do Hwa to get married so they could enter the Guardian Ship and look for clues there.
Both Ahn Yoo Na and Lee Do Hwa, have specific goals in the Guardian Ship. Ahn Yoo Na was looking for clues to Julian Park's death as well as finding out who was behind the murder of her brother Ahn Yoo Seon who was also an NSS agent who died while investigating the same case three years ago. As for Lee Do Hwa, he also has a motive why he can join this mission. Ferry Park was the last person who was with his wife Han Ji Eun's killer. Lee Do Hwa wanted to find out where his wife's killer was.
They both go to the Guardian Ship to meet Ferry Park on a secret mission from the NSS despite personal motives behind it. Ferry Park was Julian Park's younger brother, the owner of the Guardian Ship that Ahn Yoo Na and Lee Do Hwa will go to.
The Guardian Ship will bring ten celebrity couples to Japan for a fundraising event as well as a celebrity event that will raise donations for the JP Care Foundation. The foundation of a subsidiary of the JP Group owned by Julian Park which is now held by his younger brother, Ferry Park.
Like a newlywed couple who are going to make their honeymoon on a cruise ship called the Guardian Ship. Lee Do Hwa and Ahn Yoo Na were picked up by a staff member of the JP Care fundraising event. They were both picked up by Ferry Park's private driver named Do Siwon.
They are both served as a real husband and wife couple. They both got married in front of a priest and registered their marriage at the civil registry office. All of this was done so that everyone believed that they were both married. Especially they have to convince Ferry Park, so they can get into the Guardian Ship and find out more clues there.