Hangover.

A company sends one of its two managers to China to sign a lucrative contract. The story begins when the manager tells the two managers that they are both good at drinking. The two of them drink to see who can drink better, but both of them are drunk. When they wake up, they wake up as three men in a military unit. They don't know why they came here, how they got there yesterday, or what they did there. Only a third guy tells them what happened to them, and when they get drunk again, the story continues to get more complicated. The story continues full of events such as how the two of them left and became three men, what the three of them did together, and so on.