Actor Kang Dong Won, why was he lonely while filming the movie ”The Designer”?

The unexpected behind-the-scenes of the movie "The Designer" has been revealed, raising expectations. The movie "The Designer" (directed by Lee Yo-seop), which will be released in Korea on May 29th, is about a man who is hired as a contract killer but dies in a perfect accident.
The story is about a designer named "Yongil" who manipulates the robots and gets caught up in an unexpected incident. The unexpected behind-the-scenes is the overwhelming presence of "Yongil", a designer who manipulates the robots and kills the robots by accident.
The fact is that Kang Dong Won, who exudes emotion, continued filming alone on set. Kang Dong Won planned the contract murder he was asked to carry out to look like a natural accident and was sent to Samgwang Security.
As the leader of the company, he will be portrayed as a perfectionist who acts carefully to protect his team members, and will be tasked with monitoring targets and leading the Samgwang Security team.
However, there were many scenes where he filmed alone rather than taking center stage. Director Lee Yo-seop said, "Yeong-il is a very lonely character who is similar to modern people, as well as a designer who manipulates accidents.
Just as the title suggests, Kang Dong Won will perfectly portray the lonely yet calm side of "Yeong-il," creating realistic empathy for the character.