Gong Hyo-jin reveals which 'cheesy' line in her new drama A Bona Fide Killer moved her

Mother by day, vigilante by night.

South Korean actress Gong Hyo-jin is back with the new K-drama A Bona Fide Killer and this time her character lives a double life.

The 46-year-old, who last starred as an astronaut in the 2025 series When The Stars Gossip, plays Yoo Bo-na, a seemingly ordinary working mum who is actually a secret lethal vigilante assassin named Kingfisher.

Her husband Kwon Tae-sung (played by Jung Jun-won) is an investigative reporter unaware of her hidden identity and is unknowingly hunting down Kingfisher.

In an interview with AsiaOne, Hyo-jin recalled her most memorable experience from filming the drama.

Spoilers ahead.

Bo-na and Tae-sung's first meeting and their dating life before marriage spans the entirety of episode eight, and Hyo-jin said filming those moments remain vivid in her memory.

"For that shoot, I had to wear a wig and we needed artificial snow. Fortunately, we got to film on a mountain where real snow was piled up to our waists, which was a true feast for the eyes," she told us.

Our interview was held prior to the episode airing, and Hyo-jin said she was curious to see viewers' reaction to the transition between trained killer Bo-na and a Bo-na who is "experiencing unfamiliar romantic feelings for the first time".

"When I first read my line 'Please be gentle with me, it's my first time falling in love,' it felt a bit cheesy, but because it expressed Bo-na's heart so purely, it really touched me," she said.

Fast forward to the present timeline, their relationship remains loving but at the same time, filled with unease.

"Although Tae-sung is hunting Kingfisher, he never suspects for a moment that the figure could be his own wife. Rather than doubting each other directly, the dynamic stays tense as they remain wary of the threats surrounding them," explained Hyo-jin.

Meanwhile Jun-won told us he hopes viewers can pay close attention when Tae-sung begins to have suspicions about Kingfisher's identity.

[embed]https://www.instagram.com/p/Dch5k3WE4Ny/[/embed]

"A key focal point will be seeing the choices Tae-sung makes and what he ultimately decides to protect while caught between his professional ethics and his responsibility to safeguard his family," he said in the same interview.

'Unlike anything I've shown in previous roles'

Jun-won, 38, previously starred in Resident Playbook (2025), a spin-off from the hit drama Hospital Playlist (2020-2021), which propelled him to fame.

He felt the "love and interest" he received from Resident Playbook served as a stepping stone to this new series.

"I haven't felt a huge shift in my day-to-day personal life yet, but I believe that delivering strong performances in good projects is my primary responsibility and I tried to immerse myself fully in filming," he said.

He felt some pressure as A Bona Fide Killer marks his first time carrying a "longer narrative arc" as a lead role, but he took things step-by-step at his own steady pace.

When asked what his most challenging scene in the drama was, Jun-won couldn't pinpoint just one because playing a married character was "a whole new challenge" for someone who is single.

"Since I don't have direct personal experience with marriage or parenting, I spent a lot of time contemplating how to naturally and convincingly portray Tae-sung as a dependable father and husband. In every single moment on set, I strove to bring true authenticity to Tae-sung's emotions and actions," he said.

For Hyo-jin, having to do action scenes was the toughest part.

[embed]https://www.instagram.com/p/DcdV68Vmp_s/[/embed]

"When I first read the script, I worried whether my action sequences could deliver that thrilling satisfaction to viewers," she said.

She got the courage to "take the leap" when the director reassured her that Bo-na relies more on sniper rifle sequences than hand-to-hand combat and her everyday life forms more of the main narrative arc.

"I also worked hard to naturally balance the dramatic contrast between her cold-blooded killer persona and her warm, affectionate self as a mother, wife, and daughter-in-law back at home," she said, adding that for Kingfisher, she prepared a "dry and unwavering demeanour unlike anything [she has] shown in previous roles".

"I tried to fluidly navigate that gap between two contrasting sides — the mother living every moment to the fullest for her family, and the cold-headed killer."

In the drama, Bo-na is skilled and known for "one shot, one kill".

Hyo-jin had a cheeky answer when we asked what she would want her "one shot, one kill" to be if she could have anything in real life.

"If I possess a 'one-shot, one-kill' ability to instantly capture someone's heart, I would want to use it right now to instantly win over the hearts of viewers in Singapore through A Bona Fide Killer."

A Bona Fide Killer is streaming on Rakuten Viki.

[[nid:743400]]

syarifahsn@asiaone.com

No part of this article can be reproduced without permission from AsiaOne.