Doug Billingham is a seasoned detective in the anime series Double Decker! Doug & Kirill. Known for his sharp instincts and analytical skills, Doug is the more experienced partner in the duo, often taking the lead in investigations. His composed demeanor and practical approach to problem-solving balance out his partner Kirill's more spontaneous nature. Despite his serious exterior, Doug cares deeply for justice and has a strong sense of duty, making him an essential member of the SEVEN-O Special Crime Investigation Unit.