Cure Marine is depicted in a dynamic mid-sprint pose that captures her speed and grace. The figure showcases flowing aqua-tinted hair with sculpted strands that cascade behind her, complemented by a streamlined sea-themed costume featuring a light blue bodice, translucent fins along the hips, and a short pleated skirt in deeper azure. Subtle pearl-like accents and seashell motifs adorn the chest and shoulders. A translucent water-effect cape or mantle sweeps behind her, catching light to mimic waves. The base echoes an underwater scene with sculpted foam, coral elements, and bubbles, grounding the character in a marine setting. The paintwork uses high-gloss blue tones with white highlights to emphasize motion and translucency, and the sculpted fingertips and facial expression convey determination and kindness.

In Heartcatch Precure!, Cure Marine joins the roster as the ocean-themed Precure who channels water-based powers to defend life in the sea and the land. Her personality blends calm confidence with a fierce commitment to protect her friends and marine creatures, often serving as a voice of reason when the group's plans face doubt. Across the season, she harnesses tides and currents to amplify her attacks and heal damaged ecosystems, learning to coordinate with the team’s Heart Catch phenomenon to reveal light against darkness. Her backstory ties to a coastal shrine connected to the ocean’s spirits, and her growth centers on balancing her serene, contemplative nature with the urgency of battle, ultimately helping restore color and harmony to the world after the villain’s schemes threaten to drain it.