It was rumored that the actors had to visit a dog training facility multiple times so that they may grow close to the wolfdogs before they officially started filming for the drama. This process was necessary as the wolves only responded to orders from their masters after undergoing professional training. So, the actors got slowly acquainted to the wolfdogs by mingling and familiarizing themselves with the wofldogs' mannerisms and characteristics. 

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The production crew said, "We were originally planning to create the wolfdogs using CGI, but to make [the drama] more realistic, we decided to cast these dogs who have appeared in a lot of movies. I think the results were more realistic and complete thanks to the actors who took the time to develop their chemistry with the dogs even before filming began." 

Check out the behind the scenes still cuts below!