Midori Makibao, also known by the nickname Unkotarezo, is the main character of the anime and manga series Midori no Makibao. He is a small, white mule who, despite being born from famous Thoroughbred racing bloodlines, possesses an extremely unusual appearance more resembling a pig's body with a hippo-like head, and is only about the size of a large dog. His physique is compared to that of a donkey, characterized by wide nostrils that distinguish him from larger, more elegant racehorses. At the beginning of his life, Makibao is a cowardly crybaby who dislikes running and depends heavily on his mother, Midoriko. After his mother is sold away to settle a debt, Makibao is forced to fend for himself. During a frightening encounter with a wolf in the forest, he defends himself in a crude manner, which is witnessed by a clever wild mouse named Chuubei. Chuubei gives him the crude nickname Unkotarezo as a result, and the two form a close bond, with Chuubei becoming his closest friend, supporter, and eventually his jockey during races. Makibao is driven by two powerful motivations: the need to defeat his lifelong rival, the talented black Thoroughbred named Cascade, and the determination to win back his mother. Despite his small, odd appearance and initial lack of confidence, Makibao compensates with immense guts, raw determination, and surprising speed. His career begins with significant difficulty and trouble making a proper debut, but through a series of demanding races, grueling training, and numerous hardships, he matures from a timid foal into a celebrated and formidable racehorse. His notable abilities include a fierce fighting spirit, an ability to dig deep for extra speed when needed, and an unbreakable will to overcome obstacles. His role in the story is that of an underdog who rises through the ranks of competitive horse racing, forming key relationships with his trainer Kansuke Yamamoto, his mother Midoriko, his rival Cascade, and his loyal friend Chuubei. Throughout the series, Makibao develops from a frightened, dependent youngster into a confident and respected champion, all while maintaining a sense of humor and a strong emotional core.