Unabara, designated by the celestial name Neptune, operates as a designer in the animal creation department. His physical presence combines a tall, muscular frame with hazel eyes, long brown hair extending to his mid-back, and a short goatee. He consistently wears a yellow button-down shirt, black tie, pink sweater vest, pleated blue slacks, brown loafers, and black sleeve garters on his upper arms. Despite his imposing build, his demeanor reveals profound gentleness and sensitivity; he reacts with visible distress to notions of animal suffering or discomfort. He perpetually carries a pale pink stuffed rabbit doll, mirroring his affinity for cute aesthetics.

His design principles prioritize crafting adorable, non-threatening creatures, with a pronounced fondness for fluffy animals. This ethos frequently clashes with Kimura, who taste-tests animal prototypes, provoking Unabara's anguish and fueling their tense relationship.

Among his creations, the kangaroo stands as his masterpiece. Additional designs encompass multiple otter species (sea otter, river otter, giant otter), the giraffe, cetaceans (dolphin, whale, sperm whale), tamandua, armadillo, narwhal, rabbit, squirrel, ground squirrel, emperor penguin, and giant panda. His emotional commitment surfaced vividly during the sea otter's development, where he passionately championed its endearing traits.

Within the team, he functions as an emotional anchor due to his compassionate nature. Colleagues acknowledge his specialization in endearing creatures, exemplified by Ueda's assertion that "cute creatures are his specialty." He sustains positive working relationships across the department, even amid creative disagreements like those during the sperm whale and giant squid collaboration. His characterization remains unwavering in official media, maintaining consistent personality and design focus without significant evolution or backstory revelations.