Actors Chae Soo-bin, left, and Yoo Yeon-seok pose during the press conference for MBC's new romance thriller series "When the Phone Rings," held at MBC in Mapo District, Seoul. Courtesy of MBC

Actor Yoo Yeon-seok will be turning into a coolheaded politician from a prestigious family in his new romance thriller series "When the Phone Rings."

Based on the web novel of the same name, the new MBC series, which premieres Friday, follows a couple married through an arrangement — emerging politician Baek Sa?eon (Yoo) and his mute wife Hong Hee?joo (Chae Soo-bin).

Baek is the youngest presidential spokesperson, who built his political career from a journalist to primetime news anchor. His three-year marriage of convenience with the daughter of a newspaper proprietor has been all about pretending to be a happy couple, all while Baek's father pursues the presidency.

A scene from the series "When The Phone Rings" / Courtesy of MBC

But when he gets a call that his wife has been kidnapped, their life turns upside down.

Yoo shared that he was drawn to the enigmatic character, which is different from his previous roles mostly in romances.

"Recently, in romance roles, I feel like I often played characters who were indecisive or warmhearted. In this script, the character is extremely rational, hides his emotions and has a cold heart," he said during the press conference for the series at MBC headquarters in Mapo District, western Seoul.

"As he faces an incident, the romance becomes very deep. As I peel back the layers of this cold character one by one, like an onion, I could feel his charm."

Yoo took personal lessons from an MBC announcer to create his spokesperson character.

"I had many new experiences (with this drama), like shooting at a news studio. Announcer Jeon Jong-hwan personally taught me passionately and I learned a lot by observing him. He was so earnest in teaching me, preparing papers and providing reference videos," he said. "I also studied press conferences and briefings of current politicians."

Chae plays a sign language interpreter who became mute at a young age after an accident.

"The genre combining romance and thriller felt new to me. And I really wanted to play Hong from the moment I met this character," she said.

"We're used to expressing things through words, but communicating through sign language was very new. The character seems passive as she lives a suppressed and difficult life, but there's a strong spirit and unique quirkiness in her, which was interesting and refreshing."

Yoo hinted at their romantic chemistry, which will escalate as the story progresses.

"Since we play a couple that doesn't even talk to each other, I didn't try to get close too quickly (with Chae). The romance builds up (throughout the story), so I tried to become familiar with each other slowly, adjusting the pace," he said.

"The chemistry explodes later on. You can look forward to it."

"When the Phone Rings" airs every Friday and Saturday at 9:50 p.m.