Waregarasu is a professor and citizen of Chicchaina, secretly opposing its authoritarian government. He discovers Melmo held captive there and aids her escape. Following their flight, he relocates to Japan, residing there for most episodes.

In Japan, Waregarasu serves as an advisor and occasional guardian to Melmo and her younger brothers. He addresses Melmo's questions about complex adult topics like human reproduction and sexuality, providing explanations and guidance. He also offers practical solutions to the challenges Melmo encounters while caring for her siblings.

In the final episode, after Melmo marries Jiro, Waregarasu proposes adopting Melmo and her brothers to return with them to Chicchaina. Melmo declines, choosing to live with Jiro's family. Consequently, Waregarasu returns to Chicchaina alone.

No official information exists regarding this character's appearance or development in other media beyond the original 26-episode anime series.