It appears Hyungsik is just fighting with everybody in drama 'High Society'... UEE, Sung Joon, and now guest star, Lee Sang Woo! 

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Actually, it turns out that to retaliate against Hyungsik for pouring water atop UEE's head, her older brother, played by Lee Sang Woo, will be making a special appearance to throw a punch at Hyungsik as a warning.  He will be playing the older brother, Kyung Joon, who only trusts and follows UEE, despite her being the black sheep of sorts in the family.

The rep promised that viewers would get to see an affectionate and sincere side to Kyung Joon that only comes out in front of his sister. It also seems his special appearance is a means to helping out Director Choi Young Hoon and writer Ha Myung Hee, both of whom he had worked with before in 'One Warm Word.'

The first episode airs on June 8!