Eganko hails from a fantastical dimension reachable via a demonic computer system, appearing as a humanoid with pointed elf-like ears. Her core drive centers on pursuing a romantic and sexual bond with Norizaku Hanyu, a human transported accidentally into her realm. After encountering Norizaku and Midori Asai, she clarifies their interdimensional entrapment and the need to find a specific key for portal reactivation. She immediately employs overt seduction tactics toward Norizaku, including nudity and explicit demands for his sperm, framing this as inherent to her reproductive biology or customs—establishing her sexually assertive nature.

Eganko transforms the ogre Kingan (renamed Tsunotaro) into a physical key once Midori subdues him. She activates the interdimensional portal by inserting Tsunotaro into her genitalia, enabling the group’s return to the human world and insisting on accompanying them. In the human realm, she persists in courting Norizaku, devising a scheme with love potions to sway his affections toward her while redirecting Midori’s feelings to a classmate. The plan collapses due to a potion mix-up, causing unintended romantic entanglements. This underscores her unwavering determination to win Norizaku through magical means and her jealousy toward Midori.

No details surface about Eganko’s origins, species history, or pre-narrative life. Her character arc remains fixated on romantic and sexual goals regarding Norizaku, without documented evolution beyond these pursuits. Her fate after the potion incident goes unaddressed.