Megumi Amano, sister to Jyaku Amano, hails from the beast-man realm. She possesses cyan hair and blue eyes, frequently attired in a short skirt that reveals her underwear. Her hypersexuality is consistent across both manga and anime continuities, though her characterization diverges significantly between these versions.

In the manga, Megumi exhibits malicious and antagonistic traits. She employs trickery to lure men into sexual encounters, subsequently accusing them of rape or consuming them in her true monster form. A petty rivalry with Akemi Itō ignites after Nagumo Tatsuo chooses Akemi over her, culminating in Megumi attempting to kill Akemi by summoning a sea demon. Her personality includes sociopathic tendencies, and she speaks with a Kansai regional accent. Her manga role remains minor, confined to two chapters without substantial development.

The anime adaptation transforms her character. While retaining her hypersexuality, it removes her manipulative and cannibalistic nature. She becomes kinder, empathetic, and more heroic, featuring prominently across multiple OVAs. Convinced Nagumo Tatsuo is the Chōjin from the outset, she protects him, maintaining a persistent romantic interest that fuels jealousy toward Akemi. She develops a genuine romantic relationship with Takeaki Kiryū, Nagumo's cousin, ultimately killing Kiryū during a battle against Münchhausen II to end his manipulation.

Her abilities include high durability and combat skills, though she often falls short against named antagonists. Post-apocalyptic narratives confirm her survival following the merging of the worlds, where she continues her journey alongside other survivors, though specific developments remain undetailed. Her narrative shifts from a minor villain in the manga to a resilient, albeit flawed, supporting character in the anime.