Ayumi Tsukishiro, whose avatar in the Aikatsu Planet system is known as Q-pit, is a main character. She is a student at a private high school, where she balances her academic responsibilities with her career as a professional idol.

In her everyday life, Ayumi is a diligent and accomplished young woman. She is a dedicated student who consistently achieves top grades in her class. Her disciplined nature extends to a strict personal fitness regimen, as she goes to the gym five times a week. Despite her high level of commitment, she is somewhat shy and awkward when others bring up her intense workout schedule. She has a beauty mark beneath the left corner of her mouth and dark brown curly hair, which she typically styles into a high braid secured with a white and pale blue scrunchie.

Her personality is defined by an unwavering work ethic. Ayumi is known as a hard worker who never complains, no matter how grueling her training becomes. She is described as polite and elegant, appearing to be perfect at everything she does. Her favorite thing is work itself. However, this polished exterior belies a driven interior; her primary motivation as an idol has been the goal of surpassing the previous top idol, Hana (originally represented by Meisa Hinata). This ambition fuels her rigorous training schedule and her relentless pursuit of the number one ranking.

Within the story, Ayumi operates under the Million Agency. Her avatar, Q-pit, is a striking figure with tea-green hair featuring turquoise highlights, braided and curled, and emerald and mint colored eyes. The name Q-pit is a stylized reference to Cupid, the Roman god of love, which connects to the meaning of her Japanese name, "love bow." As Q-pit, she specializes in Horoscope-type Swings, a strategic choice because they are strong against the Flower-type Swings preferred by her rival, Hana. Her key Dressia is Love Sagittarius.

Ayumi's role in the narrative is closely tied to her rivalries and friendships. Her most significant relationship is with Meisa Hinata, the original user of Hana. Their competitive rivalry is a major catalyst for Ayumi's growth, as constantly pushing each other to improve allows them both to reach new heights. This bond is so strong that their mutual respect and drive cause their respective Dressia to evolve into more powerful forms. She also shares a close relationship with the younger idol Ann Kurimu, who deeply admires Ayumi to the point of seeing her as a goddess. Ann works hard to earn the right to address Ayumi and her avatar familiarly. Ayumi also forms a unit with Ann called Lovely Marron, and she is supportive of other idols like Mao Otoha (the new Hana).

Throughout the series, Ayumi experiences significant development. She begins as a rookie idol with the singular goal of becoming number one, a position she achieves early on. Her abilities are not just limited to her strategic mind and physical training. She is an accomplished actress, able to convey complex emotions non-verbally, as demonstrated when she won the lead role in a film adaptation of Cinderella through a powerful performance. Her hard work is shown to be the result of consistent effort rather than just innate talent. The "Q-pit Road," a path formed on a hill by her repeatedly walking the same route during jogs, serves as a powerful metaphor for the dedication required to reach the top. She has played the piano since she was young, which has given her perfect pitch. Her notable abilities also include a sharp attention to detail, allowing her to notice subtle changes in an opponent's performance. By the time of the Planet Princess Grand Prix, Ayumi considers putting her solo activities on hold to focus on her unit with Ann, demonstrating a shift from purely individual ambition to collaborative growth.