Actor Park Seo Joon found a hilarious and creative way of promoting his new film, 'Concrete Utopia'. 

On July 21 KST, Park Seo Joon used his Instagram story to "call out" a mysterious Instagram user. He wrote, "Who the heck are you?", and tagged the Instagram page of a user named Minseong (@min_castle0809). 

So who is Minseong?

First, his profile reads, "Nick and Judy couple's newlywed life." 

The description of his profile image reads, "A cherry  blossom date with Myunghwa in the neighborhood. Kekeke the way she's hiding behind me is kinda cute." 

Did you figure it out? Minseong is the fictional character played by Park Seo Joon in the new blockbuster disaster film 'Concrete Utopia'!

In the story, Minseong is married to Myunghwa, played by actress Park Bo Young. It seems that Minseong's Instagram account was created for purposes related to the movie. 

Fictional person or not, Park Seo Joon is pretty serious(?) about the existence of a doppelgänger. He wrote on Minseong's Instagram, "I asked, who the heck are you. You know what, let's never face each other in real life. Or else one of us might be put in real danger." 

Meanwhile, 'Concrete Utopia' premieres in theaters across South Korea on August 9!