Noelle is an angel-in-training and the main protagonist of her series, characterized by hyperactive energy, naive innocence, and perpetual happiness. Though lacking in intelligence, her deep kindness balances these traits. A floating halo marks her incomplete angelic status. Her core motivation ignites upon meeting Yuusuke Kamoshita in a forest, sparking an enduring romantic fixation. She vows to become his personal angel and marry him, driving her actions throughout the narrative.

She originates from a non-human family: a Frankenstein-like father, a mother with occasional witch-like traits, a vampire brother (Gabriel), an invisible older sister (Sara), and a younger elven sister (Lucca) who invents as a child prodigy. This family abruptly relocates into Yuusuke’s home, replacing it with a large plastic-like castle and disrupting his life. Her witch grandmother, Granny, disapproves of Noelle’s affection for humans, particularly Yuusuke.

Noelle’s daily life centers on relentless attempts to achieve flight—a requirement for full angelhood—often using makeshift wings or runways crafted by Lucca. These efforts consistently fail. She pursues Yuusuke with unwavering persistence, demanding hugs and declaring catchphrases like "Yuusuke Yuusuke Yusuke!", "Yusuke gyutte shite" (Yusuke, hug me), and "Tenshi ni narumon!" (I will become an angel!). Her attachment manifests physically through frequent glomping.

Her journey faces opposition from antagonists Dispel and later Silky. Dispel, initially perceived as the primary foe, kidnaps her repeatedly to thwart her angelic ascension, fearing her success. These plots are always foiled by her family. Silky, revealed as Dispel’s puppeteer, emerges as the true adversary, actively sabotaging Noelle’s training. The narrative climax unveils Noelle, Silky, and Mikael as fragments of a single shattered angel-egg, destined to ascend collectively or not at all. Silky resists this fate, but Noelle persuades her to embrace their unity, enabling their joint ascension.

Noelle’s relationship with Yuusuke evolves from unrequited obsession to mutual love. Initially dismissive of her affections while preoccupied with his crush on classmate Natsumi Suzuhara, Yuusuke gradually reciprocates, cementing them as the series’ official couple by its conclusion.

She maintains generally positive family bonds, acting as a childish older sibling to Lucca. Conflicts arise with characters Rena and Nyu due to their negative attitudes. A notable friendship forms with "Nick Jr Face" during a game-playing encounter. Her sister Sara develops feelings for Mikael, though his primary connection remains with the angel Raphael.

Noelle’s development revolves around her persistent, simplistic pursuit of angelhood and love for Yuusuke, confronting external threats and internal doubts. Her pivotal role involves uniting the three angel-egg fragments, demonstrating resolve and leadership in convincing Silky, and transitioning from a flight-obsessed trainee to a catalyst for collective ascension.