is a japanese video game designer. at one time, he worked for sega. ōshima designed and created the characters for sonic the hedgehog and dr. eggman. yuji naka and hirokazu yasuhara are often given credit for his work on the "sonic" series because of their close association with the sonic name. ōshima became well known at sega's sonic team for creating characters and playing an important part in the development of games like "phantasy star", "sonic cd", "nights into dreams...", and "sonic adventure".