Tsuchiya heads the Animal Design Department at the Heavenly Creative Agency, directing the creation of animal species per client specifications. As one of the design team's oldest members, he appears elderly with white hair, glasses, and a frail build. He consistently wears a traditional blue-and-yellow patterned yukata with rounded sandals, maintaining a traditional aesthetic.

His defining trait is a recurring obsession with horses, which he considers his magnum opus. This fixation drives him to propose horse-based variants like unicorns, Pegasus, zebras, and seahorses for new requests. However, these concepts often face rejection due to biological flaws—Pegasus wings demanding unsustainable muscle mass, or unicorn horns causing calcium deficiencies. Despite these rejections and occasional project delays, his team actively supports and encourages his contributions.

Beyond equine designs, Tsuchiya demonstrates versatility by crafting animals like wolves and white rhinoceroses. He leads client negotiations and develops team strategies for complex projects while mentoring junior designers such as Mercury, sharing his extensive expertise. Though horse-centric ideas dominated his early work, his scope expands across official media to include more diverse, biologically viable creations.

Tsuchiya shares a close bond with his grandson Kenta, who occasionally visits the department. Kenta’s childhood drawings sometimes inspire approved animal designs, and their mutual love for horses deepens their connection, showcasing Tsuchiya’s familial pride and warmth.

Narratively, his initial horse obsession wanes over time. Early segments emphasize his repeated equine proposals, while later developments reveal his broader animal contributions and adaptable teamwork. His consistent leadership anchors the department amid creative turbulence.