Sonic the Hedgehog Settei Shiryoushuu
From Sonic Retro
Sonic the Hedgehog Settei Shiryoushuu (設定資料集) is a multi-page art guide which was distributed internally at Sega during the early days of Sonic. It features illustrations of Sonic and other characters in the Sonic universe such as Eggman and select badniks. It was scanned by former Sega employee Tom Payne.