Lee Kyu-hyung says he lost 10 kg for 'Mousetrap' role with help of 'modern medicine'

Actor Lee Kyu-hyung said he underwent a dramatic weight loss to prepare for his role in the Netflix series "Mousetrap."

A press conference for the series was held Thursday at Hotel Naru in Mapo-gu, Seoul, with director Kim Hong-sun and actors Ryu Jun-yeol, Sul Kyung-gu and Lee Kyu-hyung in attendance.

"Mousetrap" is a chase thriller following a novelist named Mun-jae, whose name, face and life are stolen by a mysterious entity known as the "mousetrap"; a loan shark named No-ja trying to recover lost money; and a detective named Sun-yong, all in pursuit of the mousetrap's true identity.

Lee plays Sun-yong, a detective who relentlessly tracks down the truth behind the case to uncover who — or what — the mousetrap really is.

Asked why he chose the project, Lee said he was hooked from the start. "When I first read the script, I thought, 'Why does this move so fast?' — and before I knew it, I was already past episode six," he said.

"In today's society, personal information is everywhere, and the thought that someone could just steal your entire life gave me chills," he added. "In that moment, I knew I had to do it."

Lee drew particular attention when he revealed he had lost about 10 kilograms for the role of Sun-yong.

"The script described the character as someone who fights well, rough and violent, so I initially gained weight," he said.

"Then I met with the director when we did not have much filming left, and he said, 'What happened to you?' He told me he had wanted me to look sharp and to lose the weight again, so I had no choice but to start losing it rapidly from that point. So I lost it again. I wish he had told me sooner," Lee said.

"I turned to modern medicine. There are a lot of good products out there, and I had no choice but to use them. I did everything I could — they come at a price, but I really worked hard at it. Afterward I was quite ill, and I am still maintaining it," he said.

Director Kim Hong-sun, who had been listening, praised Lee's performance range. "I naturally assumed that because Sun-yong is full of anger, full of grievances and has a sharp personality," Kim said. "Lee showed the wide spectrum of performance he always delivers — and he did it again this time."