Poporon served as Pekola's subordinate in the celestial hierarchy. When Pekola descended to Earth and lost her halo, Poporon ascended in rank. To permanently secure her elevated status and prevent Pekola's potential return, Poporon plotted to eliminate her former superior, motivated by a desire to maintain the authority and privileges gained during Pekola's absence.

Unlike conventional angelic portrayals, Poporon exhibited cruelty, severity, and pronounced self-centeredness. She demonstrated a willingness to kill Pekola to achieve her ambitions. Her demeanor toward ordinary humans appeared less overtly hostile, yet she displayed apprehension towards Yurine Hanazono's extreme behavior, indicating selective caution. Poporon also maintained a pre-existing animosity toward the angelic subordinate Pino.

During their initial Earth confrontation, Poporon deceived Pekola with a warm greeting, pretending to facilitate her return to Heaven before revealing her true intent and attempting to kill Pekola with a rocket launcher. Jashin-chan's arrival interrupted the attack. An enraged Poporon callously caused Jashin-chan to drop a bowl of curry, triggering Jashin-chan's intense reaction. Jashin-chan then overpowered Poporon, bound her with tape, and threw her off a cliff. Poporon later returned seeking revenge against Jashin-chan, who failed to recognize her. After Poporon caused Jashin-chan to spill groceries, including a dessert intended for Yurine, Jashin-chan retaliated by consuming Poporon's halo. This act stripped Poporon of her angelic powers, rendering her permanently stranded on Earth. Powerless, Poporon abandoned her vengeful pursuit.

Stranded without her halo, Poporon adapted to mortal life, taking employment at a ramen restaurant under the alias "Noelle Amatsuka". Pekola, encountering her there and recognizing their shared predicament, proposed a temporary truce and collaboration until their halos regenerated. Poporon rejected this offer, insisting on working alone. Her cover as "Noelle" was compromised when Yurine and Jashin-chan visited the restaurant; Poporon accidentally revealed her true identity to Jashin-chan. Yurine explicitly stated she detected Poporon's non-human aura. This encounter reinforced Poporon's wariness of Yurine. Beyond her ramen shop work, she pursued a secondary career as a pop idol. Her trajectory depicts a shift from celestial schemer focused on usurping power to a grounded figure navigating human existence through menial work and entertainment pursuits, while maintaining rivalries and cautious interactions with other supernatural beings.