Actress Kim Hee-sun revealed the secret behind her long-standing friendship with her close sister Song Hye-kyo.

Ahead of the release of the movie "A Little Warmth: 7510" (directed by Lee Han), Kim Hee-sun engaged in a virtual interview on the 10th, sharing various stories about the film.

During the interview, Kim Hee-sun discussed the key to her enduring friendship with Song Hye-kyo, who attended the VIP preview of the movie. She said, "We don't necessarily meet each other every day, but we often communicate through calls." She continued, "After watching this movie, I asked her how I came out, if I did well. She said, 'You don't need to worry, unnie.' She would send me good articles and links when I felt anxious. She's truly like a younger sister, but the way she makes an effort to comfort me when I'm worried is so lovely."

She went on to explain, "I have a strong personality. I talk a lot and chatter, while Hye-kyo is very calm and listens quietly. Surprisingly, I act cute towards Hye-kyo a lot. The roles of older sister and younger sister have somewhat reversed. We both enjoy drinking wine and having a drink. We both love dogs. Our likes are quite similar, so I think our friendship will last a long time."

"A Little Warmth" tells the story of how genius pastry researcher Chi-ho (Yoo Hae-jin), who only knows snacks, meets the optimistic-minded Ill-young (Kim Hee-sun) who only knows straightforwardness, leading to a variety of changes in the flavors of life. The film is set to be released on the 15th.