Okubo Naoya, also known as The King of Combat, is the Absolute Champion of the Ultimate Fight MMA promotion. He represented Muji TV as their affiliated fighter during the Kengan Annihilation Tournament. Two years later he entered the Kengan Association VS Purgatory Tournament as a representative for the Kengan Association. During his time at the Kengan Annihilation Tournament, he formed a circle with Kaneda Suekichi, Himuro Ryo, and Rihito referred to as the "Four Stooges". Naoya is a goofy, light-hearted man, considered by many to be less than intellectual as evidenced by his stubbornness in playing Shogi to the point of losing composure. His personality is quite like Lihito, with the two getting along with one another mainly predicated on their shared perverted and lecherous interests.