Sumika Warakubami belongs to the Warakubami family within the Hundred Devouring Families conglomerate, which specializes in entertainment. Her family's deep roots in this field heavily influenced her path. She moved to the United States at age 12 to attend drama school and audition. She debuted on stage at 13 and earned her first onscreen credit at 14. Her breakthrough came portraying a character with twenty-one split personalities in the TV show "Mistral," earning critical acclaim. By 17, she secured her first leading role in "The Gamble Hole," establishing herself as a top Hollywood actress under the stage name Kawaru Natari. Despite her international fame, she maintained ties to the Momobami clan, participating in childhood gatherings and gambles with relatives including Kirari Momobami, Ririka Momobami, Terano Totobami, and Erimi Mushibami. During one gathering, she witnessed Kirari and Ririka swapping identities; Terano sought her analysis, but she could not distinguish between the twins. Sumika displays two distinct appearances. At Hyakkaou Private Academy, disguised, she presents as pale-skinned with long, unsettled black hair covering her head, purple eyes, and a hospital mask obscuring her mouth. She often stands hunched, casting dark shadows, perceived as eerie or mysterious. Her real appearance contrasts sharply: refined features with dark brown or maroon hair featuring two long curly locks reaching her chest, appearing velvety under light. Her wide, striking purple eyes are complemented by a beauty mark under her right eye and red lipstick, aligning with her acting career's glamorous persona. Her personality shifts between identities. Initially at Hyakkaou, she appears quiet, observant, and reserved, rarely speaking but commanding attention when she does. She prefers poker, avoids initiating actions, and often follows others while analyzing their behavior. As her true self, she exhibits confidence, perceptiveness, and fairness. She disdains individuals seeking fame without genuine talent, particularly criticizing idols like Yumemi Yumemite for superficial aspirations. However, she respects those demonstrating authentic dedication to their craft. During gambles, she avoids cheating, insists on equal footing, and neutralizes biased audiences to ensure fair outcomes. She values self-determination, acknowledging Yumemi's resolve to pursue her own path. Her acting skills make her genuine emotions difficult to discern. Sumika arrives at Hyakkaou Academy during the student council presidential election, aiming to dethrone Kirari Momobami as clan leader. Initially, she remains in the background, gambling minimally and observing others. She accompanies Rin Obami during his match against Kirari, later commenting on Kirari's pleasure-seeking nature. Her involvement intensifies when she reveals her Kawaru Natari identity to challenge Yumemi Yumemite and Yumeko Jabami in a three-round arts competition called "Active Station." In the first round, a singing competition, Yumemi and Yumeko perform a pop routine, while Sumika sings "Amazing Grace" a cappella, winning overwhelmingly (92–8) despite Yumemi's audience bribery. Sumika tasks Rei Batsubami to counter-bribe the audience, ensuring neutrality, and mocks Yumemi for underestimating actresses. The second round involves eating macarons, one filled with hot sauce; Sumika hides her reaction flawlessly, while Yumemi breaks her own finger to mimic pain. Sumika deduces Yumemi's tactic, and Yumeko identifies Sumika's spicy macaron, resulting in a tie. In the third round, a card game, Sumika exploits the disconnect between Yumemi's lies and Yumeko's truth-telling, anticipating victory. However, Yumemi regains resolve with fan support, leading Sumika to lose. She accepts defeat graciously, encouraging Yumemi to pursue her Hollywood dreams. Following the gamble, Sumika departs the academy prematurely, citing commitments to a new Hollywood film. Before leaving, she transfers all her election votes to Erimi Mushibami, citing Erimi's cuteness and a desire to make the election more competitive. This act underscores their close relationship, noted by others as Sumika historically spoiled Erimi during clan gatherings. She shares a bond with Rin Obami, accompanying him during gambles and engaging in mutual respect, though her primary loyalty remains to her career over clan politics.