Anyone who has a dog will experience heartbreak at least once -- letting your beloved companion go. But it’s not so easy to make a film dedicated to your dear dog.

Jason Kim, the filmmaker behind the 2017 action comedy hit “Midnight Runners,” is releasing “My Heart Puppy,” a canine-themed film based on his own personal experiences of separation from his 10-year-old Yorkshire Terrier.

“I raised two dogs called Rooney and Ray, small Yorkshire Terriers less than 1.5 kilograms, since 2005. But as I go through various stages and events in my life, such as going to the military and continuing my career, I always felt a sense of guilt and I felt sorry for having to leave my dogs behind at my parent’s house,” Kim told The Korea Herald during an interview in Seoul on Feb. 17.

“My Heart Puppy” revolves around the efforts of Min-soo (Yoo Yeon-seok) and Jin-guk (Cha Tae-hyun) to find a new family for Min-soo’s dog Rooney, after discovering that Min-soo’s fiance is allergic to dogs.

Once the film embarked on promotions and held press screenings, it’s central topic and theme went viral among pet owners.

“There are some 15 million people in South Korea raising dogs and opinions will vary, of course. Some may say that they would hand over their dogs to new owners while others may have no choice but to look for a new owner. What I want to say is that, there is no right or wrong answer. But one should take responsibility when you keep dogs as a companion,” said Kim.

“I wanted to shed light on the stories of abandoned dogs and have a positive influence on how pet dogs should be taken on with responsibility,” he added.

The film contains a few notable lessons on friendship with dogs and how humans should view them as companion, not just a toy that you can abandon.

In the film, Min-soo and Jin-kook embark on a journey to Jeju Island looking for a new owner who can take care of Rooney. On the way, seven other dogs join as two men continuously meet puppies in danger.

“Each dog appearing in the film carries a message. For example, a pug by the name of Thor is characterized as a dog who is abandoned at a dog shelter with no nails because his owner pulled them off after he kept scratching the floor. I wanted to show how many once popular breeds are easily found at shelters once the popularity wanes, just like the Goldendoodle,” he said.

Kim said that his genuine goals of making this film were also well-shared with the actors.

"I thought the sincerity of the film’s key message had to be portrayed in a low-budget way, so that the film's message can be less swayed or influenced by external factors. I had to ask the actors to lower the amount they would normally get paid for appearing in the film and thankfully, both Cha and Yoo agreed,” said Kim.

Kim Yoo-jung, who makes a cameo appearance in the film as a character delivering an important message to the audience, also stars in the film without pay.

“Kim, who adopted a dog from the shelter long before shooting the film, had promised me to appear in the film because it was for a good cause and she also deeply understood the film’s message and purpose,” Jason Kim added. The film, originally planned for shooting in 2019, went through various setbacks in terms of casting and investment until it began with a totally new cast member in May, 2020.

Cha and Yoo demonstrate the “bromance” chemistry two somewhat foolish men with pure hearts, part of Kim’s signature style and theme, just like in “Midnight Runners.” The 2017 film tells a story of two righteous and apathetic young men who attend the police academy and their involvement in rescuing a woman after they witness her kidnapping.

“The title ‘My Heart Puppy’ not only refers to the dogs, but also symbolizes these two men who are much like dogs -- they are innocent, pure and sometimes vulnerable to modern society’s values. Throughout the film, I think Yoo and Cha effectively portrayed the message that sometimes, we need to view the world like puppies,” Kim said.

Jason Kim’s “My Heart Puppy” opens in local theaters on March 1.