Tsuchiya is Hijiri Koganei's deeply loyal and caring chauffeur. He cuts an imposing figure with his taller-than-average stature, tanned skin, neatly combed-back black hair, and a distinctive padlock-shaped beard. His professional presence is accentuated by a constant uniform of a formal black suit, white shirt, tie, and sunglasses, complemented by a deep, sensory voice. Professionally serious and upright, he treats others, especially Hijiri's friends, with consistent politeness and respect. He displays genuine emotional responses when Hijiri expresses gratitude, revealing his deep investment in their relationship. Tsuchiya possesses the uncanny ability to appear instantly beside Hijiri when needed and demonstrates skilled hand-to-hand combat capable of immobilizing opponents. His driving history includes multiple license revocations, partly stemming from incidents where individuals deliberately threw themselves in front of his vehicle to attract Hijiri's attention, landing him on a watch list. Beyond driving, Tsuchiya occasionally offers Hijiri romantic advice, sometimes positioning himself as a lighthearted, handsome romantic option relative to others. He genuinely acknowledges Anzu Hoshino's positive influence on Hijiri's personal growth and appreciates her presence. Tsuchiya also exhibits a capacity for dry humor within his interactions with Hijiri and his peers.