On June 3, Kim Bum attended a press conference for his upcoming tvN crime drama, "Hidden Identity." Reporters were surprised by his thinner appearance, which was the result of 31 lbs. (14 kg) of weight loss. The 25-year-old star endured drastic weight loss for his role as Cha Gun Woo, a former SWAT and SEAL team member, who is driven by revenge.

A report published by Moneyweek documented his responses during the press conference. "My character, Gun Woo is cold-hearted," he said, in response to questions about his weight. "I lost 14kg to match his appearance."

He described Gun Woo as a man whose drive caused him to become animal-like in appearance. Through his aggressive dieting, him looks drastically different than his previous boyish image. While he did specify his current weight, the last statistics listed on his King Kong Entertainment page, Kim weighed 145 lbs (65kg).

His portrayal of Gun Woo serves as his K-Drama return, following the 2013 period drama, "Goddess of Fire." He gained Hallyu stardom after the meteoric success of "Boys Over Flowers." His recent projects prior to "Hidden Identity" include the Chinese drama, "The Micro Era of Love."

Fans of the Hallyu star positively responded to his transition for the role, after he posted photos taken prior to the press conference, on his social media accounts. The juxtaposition of his former and current weights can be seen on his Weibo account, where he posted photos from an April 17 event in China.

The crime series chronicles the caseload of a police unit known as Investigation 5, whose mission is battling violent crimes through undercover operations.

"Hidden Identity" also stars Park Sung Woong (She Is Wow), Yoon So Yi (IRIS 2), and Lee Won Jung (The Girl Who Sees Smells).

"Hidden Identity" premieres on June 16. The drama will air on Mondays and Tuesdays in the time slot previously occupied by "Let's Eat 2."