Momoe Sawaki is a kind-hearted, polite, and thoughtful individual, often admired for her charm and emotional maturity. She exhibits a strong sense of justice and is quick to defend those she cares about, even in difficult situations. Her selflessness and bravery are evident in her actions throughout the series, particularly in how she prioritizes others’ well-being over her own. She is also perceptive and intelligent, often acting as a voice of reason especially when tempering the impulsiveness of others, such as Rika Kawai.

Despite her composed exterior, Momoe harbors deep insecurities, especially regarding her appearance. Her tall frame, androgynous features, and signature beauty mark often cause others to mistake her for a boy, a source of emotional distress for her. She is uncomfortable with the attention she receives from girls who admire her “masculine charm,” believing she is misleading them by not matching their expectations. This tension between her outward appearance and internal identity is a recurring source of inner conflict.

Her sexuality is portrayed with subtle ambiguity. While the narrative hints that she may be attracted to boys, she also demonstrates complex emotions in situations involving admiration from girls. This ambiguity is most evident during her interaction with Kaoru Kurita, a trans boy who expresses romantic interest in her with full knowledge of her gender. Though visibly embarrassed, Momoe does not reject Kaoru’s feelings outright, marking the moment as one of rare emotional vulnerability and possible acceptance.

Momoe Sawaki is a tall and slender girl with a distinct androgynous appearance. She has short auburn hair, typically swept to the left side, and dark green eyes. Her physique is notably toned for her age, with broad shoulders and a lean frame features that set her apart from the other, more petite protagonists. These physical traits often contribute to her being mistaken for a boy.

Her typical outfit consists of a navy blue sweater worn over a white dress shirt, paired with loose beige slacks. She completes her look with navy socks and burgundy shoes. The combination of her attire and appearance reinforces the common misconception about her gender, which becomes a recurring theme in her personal story.

Before the events of Wonder Egg Priority, Momoe Sawaki was close friends with a girl named Haruka, the person she now seeks to revive through the Wonder Egg system. While most of her classmates viewed Momoe as masculine or androgynous, an observation that deeply troubled her, Haruka was the first to genuinely see and accept her as a girl, encouraging her to embrace her femininity. Their friendship brought Momoe comfort and a sense of identity, but it took a complex turn when Haruka confessed her romantic feelings and asked Momoe to touch her. Caught off guard and unsure of how to respond, Momoe rejected her outright. Shortly afterward, Haruka died by suicide for reasons that remain unclear, though Momoe continues to carry guilt over their final interaction.

Following Haruka’s death, Momoe became increasingly distressed by the way others perceived her. She began dressing in a more traditionally masculine style and adopted the masculine Japanese pronoun boku, a choice that reflects her complex relationship with gender expression. Despite this, she still desires to be recognized and accepted as a girl.

Throughout her experiences in the Egg World, Momoe encounters and ultimately rejects the romantic advances of several girls, including schoolmates and two Wonder Egg girls, Miwa and Mizuki. These incidents further highlight her inner conflict and discomfort with how her appearance leads others to misunderstand her identity.

Momoe is also the niece of Shuichiro Sawaki, Ai Ohto’s art teacher. After meeting Ai, the two quickly formed a close friendship, Ai being one of the first people since Haruka to acknowledge and accept Momoe as a girl from the outset.

In the Egg World, Momoe Sawaki fights using a spear-like weapon. While its original form is not explicitly confirmed, it is suggested to be derived from an umbrella, as the weapon can unfurl into a canopy that functions as a defensive shield. This dual-purpose design allows her to shift between offense and defense with agility and precision.

Momoe also carries a pomander, which hatches into a creature resembling a crocodile. She names this companion Panic, and it assists her during battles by providing additional support and protection.