- Fast Developing Plot -
Yang Jeongin - Jeongin believes he grew up in Busan with a perfect life, his best friend always being Han Jisung. He trusts that if anything serious had happened, his parents would have told him.
Kim Seungmin - Jeongin's childhood best friend from Seoul. They were inseparable until a tragic event led Jeongin's parents to move him to Busan, erasing his past and friendships.
Han Jisung - Originally from Malaysia, Han moved to Busan for a short time and became close with Jeongin. Determined to stay, he convinced his parents to move permanently, keeping their friendship alive.
Lee Minho - Another childhood friend from Seoul, Minho was with Jeongin during the accident that forced him to move. Years later, Minho relocated to Busan but kept Jeongin's past a secret.
Chris Bahng - A guiding figure for Seungmin, balancing his responsibilities between him and another struggling friend. However, his efforts backfired, causing Seungmin to distance himself.
Seo Changbin - Chris's younger brother figure, who grew attached to him for the sibling bond he never had. Wanting to repair Chris and Seungmin's friendship, he befriends Seungmin and tries to bring them back together.
Hwang Hyunjin - Focused on himself and avoiding drama, Hyunjin meets Jeongin at his favorite dance studio. He unknowingly becomes Jeongin's escape from his past by teaching him dance.
Lee Felix - Deeply loyal to Hyunjin and unexpectedly close to Seungmin. Though he wasn't part of Seungmin's past, he's determined to understand and support him through it.