Serena Jounouchi debuts at age 14 in *Pretty Rhythm: Aurora Dream* and reappears at 18 in *Dear My Future*. Born to French businessman Steven Jounouchi and Japanese mother Karen from Kyoto, she resides in Kyoto but spent part of her childhood in France. She possesses fair skin, sharp blue eyes, and short blonde hair, styled with bangs brushed left. By *Dear My Future*, her hair grows slightly longer, fanning outward with reshaped "intake" bangs. Competitive, impulsive, and prideful, Serena displays a quick temper and easily bored nature, openly mocking those she considers inferior. She speaks the Kawachi dialect of Osaka Japanese. Her primary rivalry targets Mion Takamine, the former Prism Queen, whom she relentlessly challenges. Despite this brashness, she exhibits unwavering loyalty to her best friend Kanon Toudou, always supporting her. Her character matures over time; in *Dear My Future*, she adopts a calmer, advisory role, guiding newer characters like PURETTY. Serena forms the unit "Serenon" with Kanon, later expanding to "Serenon with K" with Kaname Chris. The unit performs Prism Shows and manzai comedy, where Serena acts as the "boke" (comedic foil) opposite Kanon. Driven by competition, she aims to surpass Mion and MARs, frequently referencing her victory over Aira and Rizumu in the Summer Queen Cup. Her Prism Show techniques feature collaborative jumps like "Hattrick Serve," "Prism Rainbow Hurricane," and "Smile Heart Dive Duet," emphasizing dynamic coordination. Her signature coords evolve from a "Gothic Devil One Piece" in *Aurora Dream* to a "Gold Devil One Piece" in *Dear My Future*, reflecting her bold, sexy-brand aesthetic. Following her original agency's dissolution in *Dear My Future*, Serena and Kanon join Pretty Top under Kyoko Asechi, continuing their Prism Star careers and manzai performances. Her development culminates in a vision of her future as a celebrated manzai comedian alongside Kanon.