[13] A blue and white collie dog named Moongchi is driven by his owner to a forest somewhere in North Korea where he is released and abandoned.

They inform Moongchi that his owner won't return which he finds hard to believe until the conversation is interrupted by a car parking nearby, leaving a scrawny crippled dog on the roadside and driving away.

They discuss their living conditions with the dangers of the dog-hunter and Gaeko mentions a distant paradise they could travel to by scent, only to be shot down by Jjangah.

The dogs bury her in the buildings dirt yard along with other past graves where they gather and mourn; Moongchi leaves to disown his tennis ball into a river.

As expected, the goat farmer calls animal control services for the wild dogs resulting in Jacob and Trevin being captured and put into a pound.

Moongchi recalls his childhood in a puppy mill where he was separated from his mother and siblings to be sold in a pet store, where he was adopted by a family who were unaware of how large he would grow.

The strays' newfound peace is short-lived as the dog-hunters find them using Moongchi's tracking device, but the dogs narrowly escape in a wildfire.

They encounter the lead dog-hunter whom they defeat in a fight and leave in the middle of the forest, the man ending up in a mine field with no way out.

The strays arrive at the border of the Korean Demilitarized Zone and see the paradise they've been seeking on the other side of the barbed fence wall in South Korea.

The film's end credits show the strays living a happy life in their new home and Moongchi and Bami eventually having a litter of puppies, and it's revealed that Jjangah has started a family with his new mate as well.

[18] Before its premiere, Underdog was sold to 69 territories including France, United States, Canada, Hong Kong, Malaysia, Singapore and Indonesia.