Yuji Naka (Naka Yūji) (born September 17, 1965) is a Japanese video game programmer, designer, and producer who was the former head of Sega's Sonic Team, where he was the lead programmer of the original Sonic the Hedgehog series of games on the Sega Mega Drive. With Sega, Naka also led development on games including Nights into Dreams (1996), Burning Rangers (1998), Sonic Adventure (1998), and three games in the Phantasy Star franchise (1987-2000). In 2006, he left Sega to found Prope, an independent game company. Naka also worked under Square Enix to direct Balan Wonderworld (2021). Naka learned how to program by replicating and debugging video game code printed in magazines. The experience prompted him to study assemblers and practice writing code during his school classes. After graduating high school, Naka decided to skip university and stay in his home town. His true breakthrough, however, came in 1991 when he programmed the original Sonic the Hedgehog game for the Mega Drive, with Naoto Ohshima designing the characters and Hirokazu Yasuhara creating the stages. The origins of Sonic can be traced farther back to a tech demo created by Naka, who had developed an algorithm that allowed a sprite to move smoothly on a curve by determining its position with a dot matrix. Naka's original prototype was a platform game that involved a fast-moving character rolling in a ball through a long winding tube, and this concept was subsequently fleshed out with Oshima's character design and levels conceived by Yasuhara. Following Sonic The Hedgehog's release, Naka moved to Sega's U.S. branch, Sega Technical Institute, where he worked with famed American designer Mark Cerny on the follow-up in conjunction with the original team back in Japan, now known as "Sonic Team". This partnership between the Eastern and Western teams continued through the development of Sonic the Hedgehog 3 and Sonic & Knuckles, though the bulk of the development duties shifted back to Sonic Team in Japan for those titles, which Naka had also returned to by that time.