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Siwan is seen showing a more mature image than fans are used to in his suit and tie that show he means business. Although his character Yoon Yang Ha is the son of a rich family and has handsome visuals, he carries emotional baggage as an adopted child.

A rep commented, "He is getting deep into his character Yoon Yang Ha and acting it out well. Even the staff were surprised and are 120% satisfied... As much as the viewers' anticipation for 'Triangle' is growing little by little, we have faith that Siwan's role will be a solid addition."

'Triangle' is the work of PD Yoo Chul Yong and writer Choi Wan Kyu,who previously worked together for 'All In' and 'Swallow the Sun'. The drama portrays the story of three brothers Jang Dong Soo (Lee Bum Soo), Heo Young Dahl (Jaejoong), and Yoon Yang Ha (Siwan), who grew up separated in different backgrounds without knowing each other's true identities and meet twenty years later.

'Triangle' will premiere following 'Empress Qi' on May 5!