Ha Yi-chan / Yoon Jung-a

Choi Seo-kyung: Impulsive and unpredictable: Acts on instinct, often committing daring and eccentric acts. Straightforward and sharp-tongued: Says what she thinks, doesn't try to seem nice or perfect. Rebel with a kind heart: Easily breaks the rules, but sincerely empathizes with the pain of others and helps the main characters. Vulnerable inside: Her feigned rudeness and sarcasm are a defense mechanism against family trauma and pressure experienced in the future.

Ha Eun-gyul: Hyper-responsibility and "savior" syndrome: Eun-gyul is accustomed to putting others' interests, peace, and safety above his own. He is pathologically incapable of selfishness, which is why he constantly scrutinizes his every move. Inner rift (double life): the character lives in a perpetual conflict between "have to" and "want to." On the one hand, he is an exemplary, quiet, and rational student. On the other, he is an emotional, rebellious, and incredibly expressive musician. Deep sense of guilt: any expression of personal freedom or self-indulgence (especially music) evokes internal rebellion and a feeling of betraying those who depend on him.

Yoon Jeong-ah: Withdrawn and detached, due to her domineering stepmother and her inability to communicate freely, Yoon Jeong-ah initially appears to be an "ice princess." She keeps to herself and hides her feelings behind a mask of indifference. Creative and profound, Jeong-ah expresses her emotions, hidden thoughts, and pain through art. The most striking symbol of her inner world is Frida Kahlo's painting "Long Live Life!" (hence the "shimmering watermelon" metaphor). Proud and independent, despite vulnerability and domestic violence, she refuses to evoke pity. For a long time, the heroine hesitates to accept help from others, trying to cope with all difficulties on her own. Loyal and capable of deep feelings, Jeong-ah is transformed by falling in love with Ha Yi-chan. She reveals herself as a sincere, gentle, caring, and incredibly brave woman, ready to protect those dear to her.

Ha Yi-chan: The "Golden Retriever" of history: He is incredibly optimistic, friendly, loud, and always brimming with energy. Yi-chan often acts on emotion, making him appear frivolous or foolish, but his kind heart is instantly captivating. A stubborn and determined romantic: To impress his first unrequited love, cellist Se-kyung, he decides to create a rock band from scratch without any basic skills. No rejection or difficulty can shake his faith in success. A devoted and loving grandson: Yi-chan is madly in love with his grandmother, who is raising him alone and runs the guesthouse "Snail House." Despite his teenage stubbornness, he deeply respects her and is afraid to disappoint her. A true, loyal friend: Friendship is not an empty phrase for him. Yi-chan is ready to rush into a fight or make any sacrifice to protect those he cares about.