Mr. Clark is a supporting character in the anime Rio: Rainbow Gate! and is best known as the grandfather of the young girl Mint Clark. He is depicted as an elderly gentleman with short gray hair, black eyes, a mustache, and a monocle, often wearing a cravat and frilled clothing that suggest a refined or traditional appearance. In the story, Mr. Clark accompanies his granddaughter to the Howard Resort, an island casino resort, where he spends his time enjoying the casino while Mint explores the premises on her own. His role is primarily that of a caretaker and familial figure; he does not participate in the central Gate Battles or possess any special abilities, nor does he undergo significant personal development across the series. His key relationship is with his granddaughter, Mint, whom he brings to the resort and with whom he shares a bond. Beyond this, Mr. Clark has minimal direct involvement with the main protagonist Rio Rollins Tachibana, as it is Mint who forms a close friendship with Rio. His motivations are not deeply explored, but they appear to center on providing a pleasant holiday for his granddaughter and enjoying the recreational offerings of the resort. Overall, Mr. Clark functions as a background character whose main narrative purpose is to introduce Mint to the setting and establish her presence at the Howard Resort.