Ruriko, a young girl tied to the phantom ship, assists the protagonist in thwarting the antagonists' schemes. Her proactive and resourceful nature proves vital in overcoming obstacles orchestrated by enemy forces. Aligned with the ship's rebellion against a corrupt corporate empire, her efforts directly undermine the antagonists' ambitions.

Though her origins remain shrouded, Ruriko shares deep connections with the phantom ship's crew. She takes decisive action during pivotal clashes, supporting the protagonist in underwater battles and aerial skirmishes. Her alliances reinforce collective resistance against oppressive regimes.

Her story is exclusively tied to the 1969 film, with no appearances in spin-offs, sequels, or adaptations. No additional backstory or expanded arcs exist beyond her role in the primary narrative's events.