Pipimi is a fourteen-year-old girl and one of the two recurring protagonists of the anime Pop Team Epic, where she appears alongside her near-constant companion Popuko. The story provides no conventional backstory for her; her background is instead built entirely through the many short, disconnected comedy sketches that make up the series. She is presented as a middle school student who drifts through both ordinary and wildly bizarre situations and reacts to them in exaggerated and unpredictable ways. In terms of appearance, she is noticeably tall for a fourteen-year-old and has large eyes, a long braid of hair, and a distinctly prominent chin. She commonly wears a sailor-style school uniform with white socks and brown shoes, matching the outfit worn by Popuko. Her hair color varies across different artwork and merchandise, appearing in blue or purple tones in some versions and dark in others.

Personality is where Pipimi's defining traits are most clearly established. She is generally very calm and composed, often described as the cooler-headed and more level-headed member of the pair. She frequently delivers flat, deadpan responses and a dry, occasionally sarcastic sense of humor, and she tends to keep her composure even in completely outrageous situations. This makes her a natural contrast to Popuko, who is more hot-blooded, impulsive, and prone to loud outbursts. In many sketches, Pipimi functions as the voice of reason, using her wits to observe, comment on, or subtly guide the chaos happening around her, often with a sharp remark aimed at anime conventions or everyday absurdities. However, she is not simply a calm straight man. She can be just as willing as Popuko to ignore rules, engage in sudden violence, or dive headfirst into the madness, and her behavior can shift dramatically depending on what a particular sketch requires. At first glance her appearance seems cute and harmless, but the series repeatedly shows that her temperament can be just as unhinged as her partner's.

Because the show is built around isolated gags and parodies rather than a continuing story, Pipimi does not have long-term goals or ambitions in the traditional sense. Her motivation within each sketch is simply to respond to whatever situation arises, whether that means taking part in a parody, reacting to a strange occurrence, arguing with Popuko, or becoming involved in some new scheme. Depending on the scenario, she can be driven by curiosity, competitiveness, or a desire to regain some control over the absurd events unfolding around her. In some stories, her experiences are far more elaborate, including plotlines involving idol management, assassination contracts, and confrontations with a shogi master, though these are played for comedy rather than treated as meaningful character goals.

In the story, Pipimi serves as one of the two central figures whose misadventures drive the series. She is sometimes identified as the leader of the pair, and she often takes on the role of the straight man or reactor who balances Popuko's exaggerated behavior. That said, the two characters frequently switch roles, with Pipimi just as capable of starting trouble as she is of reacting to it. Her presence is also essential to the show's humor, as her calm and deadpan delivery makes the increasingly ridiculous events around her even funnier by contrast, and her sharp tongue allows the series to poke fun at various subjects through her commentary.

The most significant relationship in Pipimi's life is with Popuko. The two are inseparable best friends who are almost always seen together, and their dynamic forms the emotional and comedic core of the show. Pipimi often finds herself having to rein in Popuko, clean up after her outbursts, or talk her out of reckless ideas, but she also willingly joins her in fights, pranks, and absurd plans. Despite their frequent arguments and mutual exasperation, the pair are consistently loyal to one another and always end up back on the same side. Other characters appear and interact with the duo across various sketches, including parodies and alternate versions of the pair themselves, but no other relationship carries the same weight as the bond between Pipimi and Popuko.

Character development in the conventional sense is minimal, since the series favors episodic comedy over long-term arcs. Instead, Pipimi's personality is flexible and changes to fit the needs of each sketch. In the original manga, for instance, her personality undergoes noticeable shifts as the plot progresses, with one chapter showing her developing a violent tendency after learning a fictional martial art, and other storylines placing her in a wide variety of absurd occupations and situations. These changes are used for humor rather than to show meaningful growth, though they do demonstrate the character's adaptability and the range of roles she can play within the series.

Pipimi does not rely on supernatural powers or superhuman strength in most of her appearances. Her primary assets are her intellect, quick wit, and verbal timing, which she uses to defuse situations, provoke reactions, or deliver cutting remarks while staying outwardly calm. Her ability to remain composed in chaotic circumstances allows her to function where others might fall apart. On occasion, the series grants her exaggerated or surreal abilities, sudden transformations, or improbable feats, but these are presented as gags rather than genuine powers. Some stories also depict her as capable of physical violence or martial arts when the comedy calls for it, reinforcing the idea that her composed exterior never guarantees a peaceful outcome.