Helen is a 16-year-old girl of dual Japanese-American heritage. Tar-chan first encounters her during a rescue from a crocodile attack. Helen boldly states her wish for Tar-chan to take her virginity as part of her quest for summer experiences. She subsequently befriends both Tar-chan and Jane, becoming part of their group. Helen contributes practical knowledge, teaching Tar-chan and Jane how to cultivate and manage a rice field. Initially an enthusiastic admirer of Tar-chan, her romantic interest shifts toward Pedro Kazmaier, one of Tar-chan's apprentices.

Helen's role significantly decreases after the transition to "New Jungle King Tar-chan," where she ceases regular appearances. She later returns as a fully grown adult woman in the final story arc. Her character resolution varies: in the manga continuity, Helen marries a character named Chikō, while the anime adaptation maintains her romantic focus on Pedro Kazmaier. Helen also participates in collective actions to protect Tar-chan, including involvement in orchestrating an animal stampede to aid him during a crisis.