Renowned Korean actor Sul Kyung Gu, who garnered millions of admissions with films like SILMIDO and HAEUNDAE, and established a strong fan base with THE MERCILESS, takes on the role of Jae-gook in THE MOON. Jae-gook, a former flight director, must ensure the safe return of the lone astronaut stranded on the Moon. 

Director Kim Yong Hwa expressed his admiration for Sul Kyung Gu's acting, stating, "I have always admired SUL Kyung Gu's performances. I wondered how Korea could have such an outstanding actor." SUL Kyung Gu delivers a powerful and heartfelt performance, exuding determination through every expression and gaze, as he battles against desperate odds to prevent a repeat of the past tragedy.

Director Kim Yong Hwa, reuniting with D.O after the successful collaboration with ALONG WITH THE GODS series, stated, "Doh Kyung Soo possesses a gentle persona while also having a very intense face. I thought that through the character of Hwang Sun-woo, we could showcase his hidden passion and determination, providing a fresh impression." D.O masterfully portrays Sun-woo, an astronaut fighting a lonely battle on the Moon, combining strength and resilience to bring various facets of the character to life in his own unique way. Kim Hee Ae, who has showcased versatile acting transformations in films like HERSTORY, MOONLIT WINTER, and TV series THE WORLD OF THE MARRIED, and gained international recognition through the Netflix series QUEENMAKER, solidifies her position as a global actress in THE MOON. In the film, she portrays Moon-young, the director of NASA's Lunar Gateway, who becomes the last hope to rescue Sun-woo. Moon-young faces a dilemma between her responsibilities as a NASA director and her desire to save the Korean astronaut. 

THE MOON presented a new challenge for Kim Hee Ae, as she had to handle unfamiliar space-related terminology and deliver performances that primarily rely on communication. Approaching the shoot with the mindset of a rookie actor eager to learn, she displayed remarkable preparation and immersive focus, impressing those around her. Director Kim Yong Hwa praised her as an actor who provided great inspiration. Kim Hee Ae's delicate expression of Moon-young's conflicting emotions and her overwhelming presence in making crucial decisions will captivate the audience. The undeniable acting prowess of these three actors generates a powerful synergy and strong chemistry that surpasses the distance of thousands of kilometers. Each character is separated by the Korean Naro Space Center, the vastness of space, and NASA in the United States, requiring the actors to convey their performances through communication and phone conversations without physically being in the same space. Director Kim Yong Hwa expressed his satisfaction with the exceptional synergy among the actors, stating, "They are all such skilled actors that even if they were acting separately, their emotions, tone, and manner were perfectly synchronized, which surprised me." He further mentioned that the actors approached the filming with emotions at a heightened level, akin to the "after" stage, allowing the audience to feel the powerful energy that carries the drama without getting exhausted.Naro Space Center's current flight director, Jung Min-gyu, portrayed by Park Byung Eun, adds depth to THE MOON. Cho Han Cheul takes on the role of the Minister of Science and Technology, despite having a humanities background, while Choi Byung Mo portrays the Vice Minister of the Ministry of Science and Technology. Hong Seung Hee plays the intern Han-byul from the celestial observation team at Mount Sobaeksan Observatory. This group of supporting cast enriches the story of THE MOON with their diverse roles and skillful performances. They skillfully navigate the various relationships surrounding the rescue mission of Sun-woo, effectively controlling the intensity of the drama and faithfully fulfilling their respective roles at the right moments. Director Kim Yong Hwa praised their performances, stating, "Everyone ran toward their individual goals with positive energy, creating a harmonious ensemble." With the stellar performances of these talented actors, the audience can anticipate a chemistry that surpasses the distance of 384,000 kilometers between the Moon and the Earth in THE MOON.