Ōki Sugiyama is a Japanese voice actor born on August 5, 1977, in Tokyo, Japan. He was previously affiliated with the talent management firm Production Agumi. Sugiyama has built a career through numerous supporting roles in anime television series and films since the early 2000s. He is known for playing the character Maroro in the Utawarerumono franchise, providing the voice for the role in Utawarerumono, Utawarerumono: The False Faces, and Utawarerumono: Mask of Truth. Another recurring role is Proto in the Ghost in the Shell: Stand Alone Complex series, including Ghost in the Shell: Stand Alone Complex, its second season 2nd GIG, and the film Solid State Society. His other notable anime credits include the role of Kum in The Tower of Druaga: The Aegis of Uruk and The Tower of Druaga: the Sword of Uruk, Walter in Project Blue Earth SOS, Karias Blerster in Noblesse, and Mentis in Captain Earth. He also voiced Taiki in Windy Tales, Tetsuya Gouda in Star Driver and its film adaptation, Usui no Sadamitsu in Otogi Zoshi, Gulliver in Eureka Seven, Ashura in Naruto Shippuden, and various characters in long-running series such as Case Closed and Gintama.