Dede acts as a guardian to Umi and Sora, youths whose aquatic abilities intertwine with unexplained disturbances in marine life. Her past echoes theirs—a childhood encounter with a sea-dwelling boy shaped her worldview, though her origins linger in ambiguity. She advocates the inseparability of humanity and the cosmos, claiming the universe can be cradled in a palm, and dismisses spoken language as inferior to nature’s raw, wordless dialogue.

Guiding the protagonists through existential currents, she navigates themes of life’s cyclical tides and humanity’s渺小 within cosmic vastness. The manga expands her ties to ancestral nude diving practices, rituals rooted in the protagonists’ lineage and their ancient covenant with the ocean. This heritage quietly molds her grasp of the story’s unfolding mysteries.

Her speech weaves philosophy with mysticism, insisting memories of the sea linger not in words but in the wind’s whispers. Her enigmatic presence channels the narrative’s reverence for nature’s ineffable truths, prioritizing wonder over dissection. Though allusions to her past brushes with cosmic forces surface, her motivations remain veiled, preserving her aura of mystery.

Across both film and manga, her guidance underscores rebirth, impermanence, and unity. She bridges human fragility and celestial currents, asserting that true comprehension demands surrendering logic to intuition—a harmony of senses over reason’s rigid grasp.