While desperately searching for his missing daughter, Hae-kwan comes across an AI satellite robot that remembers sounds from all over the world. Rejuvenated by the robot's abilities, Hae-kwan begins to track down his daughter's voice. As they continue their journey, they form an unforgettable bond.
Hae-Gwan
Sori (voice)
Ji-yeon
Yoo-joo
Jin-ho
Goo-cheol
Underground Singer
President Go
Hyeon-soo
Hyun-sook
Yoo Sung-jin
Jang Geun-yeong
NIS agent
NIS agent
NIS agent
Police
U.S. military officer
Grandmother
Yoo-joo's Friend
