Megumi Ayase is the reigning top star at Parthenon Productions before Creamy Mami's arrival. She possesses long brown hair, blue eyes, and signature makeup featuring red lipstick and violet eye shadow, typically performing in a dark pink stage dress with white frills. Her personality blends outward arrogance and spoiled behavior with strong determination and high professional standards. Creamy Mami's rapid ascent challenges Megumi's position, fueling professional insecurity and jealousy that cause her to question her methods and occasionally resort to underhanded tactics.

Her central conflict stems from rivalry with Creamy Mami, who overshadows her popularity and captures the attention of Parthenon President Shingo Tachibana, the object of Megumi's romantic feelings. Shingo's open favoritism towards Creamy Mami frequently triggers Megumi's frustration, leading to confrontations and physical reactions like slapping him, a recurring comedic element.

The spin-off manga *Magical Angel Creamy Mami and the Spoiled Princess* delves deeper, revealing through flashbacks that Megumi co-founded Parthenon Productions with Shingo through years of mutual hard work and dedication. This starkly contrasts Creamy Mami's seemingly effortless success. The manga details Megumi's grueling daily routine of exercise, practice, and image maintenance, showcasing her deep professionalism and career commitment. It reframes her antagonism as a reaction to Shingo's manipulation: he deliberately pits her against Creamy Mami, undermines her by labeling her a "spoiled princess," and dismisses her contributions, fostering a toxic work environment that intensifies her resentment.

Her character evolves beyond the original series. In the 1985 OVA, set after Yuu Morisawa (Creamy Mami) has permanently aged to 16 and lost her magic, Megumi collaborates with her on a film project, indicating a shift from outright rivalry towards a more professional, though likely complex, working relationship.