Serena is a calm and coolheaded mermaid with a quiet, serious nature, harboring a subtle self-consciousness about her perceived clumsiness. Her closest bond is with Fina, whom she cherishes as a shell-sister and regards with the reverence of an older sibling. This relationship anchors her interactions, fostering a harmonious dynamic of unwavering support and familial loyalty within their close-knit group.

She resides among five young mermaids navigating the rhythms of daily life in a vibrant underwater world, where stories prioritize shared adventures over individual histories. Her origins and personal growth remain unexplored in extended narratives or supplementary media, reinforcing her role as a steady, reserved presence within the ensemble. Through her thoughtful demeanor and deep connections, she enriches the slice-of-life narrative centered on communal bonds.

Her design adheres to the series’ mermaid aesthetic, featuring pale azure hair and eyes that mirror oceanic hues. Graceful poise and understated elegance define her mannerisms, though specifics of her attire or visual variations remain unchronicled. Rooted in the core series, her character embodies simplicity and sincerity, reflecting the tranquil essence of her underwater existence.