Nemu Asakura is a petite young woman with short auburn hair and teal eyes. She consistently wears her school uniform, accessorized with two yellow ribbons on each side of her head and a black choker featuring a small yellow bell—a sentimental childhood gift from her step-brother, Jun'ichi Asakura.

Her demeanor is typically polite and friendly, but she reveals possessive tendencies and intense jealousy when other girls express romantic interest in Jun'ichi. This jealousy triggers a shift into a colder, antisocial persona dubbed "Dark Nemu" or "hidden Nemu," where she adopts an excessively formal and distant attitude. Proactive and hardworking, she participates actively in school committees like discipline and health. Yet she harbors a short temper, reacting with childish violence when provoked, especially in conflicts involving Jun'ichi.

Notably, Nemu possesses lethally poor cooking skills, leading Jun'ichi to privately call her the "Murderous Chef." Her relationship with Jun'ichi anchors her character arc; though step-siblings, she nurses deep romantic feelings for him. This fuels recurring tension with Sakura Yoshino, whom Nemu views as a rival due to Sakura's closeness to Jun'ichi.

In the broader Da Capo timeline, Nemu eventually marries Jun'ichi. Their union produces granddaughters, Otome and Yume Asakura, who emerge as main characters in the later-set *Da Capo II*. Nemu's eventual death forms part of *Da Capo II*'s canonical backstory, though its cause remains unspecified.

Within the spinoff *T.P. Sakura - Time Paladin Sakura - Jikū Bōeisen*, Nemu appears in a supporting role. This OVA features a younger Sakura Yoshino as a third-grade magical girl wielding time-travel abilities, but Nemu's involvement adheres strictly to her established traits and relationships from the core *Da Capo* continuity.