Cheon Woo-jung, searching for a high-paying, short-term job, finds work as a cruise staff member. There, he encounters a passenger who changes everything.

"Do you also do interpretation?"
"English, and… a little Filipino."
"Are you willing to use your mouth for me, Mr. Cheon Woo-jung, and take my money?" the man proposed.

Woo-jung needed money, and the man said he needed Woo-jung's mouth. So, all the misunderstanding was Woo-jung's fault for taking his words literally.

"Now, shut your top mouth and open your bottom one."
"...Huh?"
"Interesting. Did you think you'd be doing something grand?"
"I think there's been a misunderstanding. I clearly remember you said 'interpretation' then…."
"When did I say that?"
"You did…."
"You're no fun when you act like this, Mr. Cheon Woo-jung. You should be crawling on all fours, begging for affection, and even that wouldn't be enough."

By the time he came to his senses, the ship was already sailing in an unexpected direction.