The Sonic Storybook Series is a collection of storybook-themed Sonic games exclusive to the Wii. In both games released under the series, Sonic the Hedgehog travels into the world of a storybook to stop a great evil that potentially threatens both his world and theirs, meeting alternate versions of his friends and enemies in the process.
With the help of a young genie named Shahra, Sonic must travel into the Arabian Nights and prevent the Erazor Djinn, an evil version of the genie in Aladdin and the Magic Lamp, from destroying the world in the book and entering his own.
The "Sonic Storybook Series" name was only used on the American version of the cover for Sonic and the Black Knight.
It is never actually explained what method Sonic uses to return to his home world after defeating the evil in either storybook game.
On the back of both box covers of the two games, Sonic is seen in the same pose.
Tails and Knuckles are the only characters besides Sonic that appear in all of the Sonic Storybook Series games in their alternate forms.
Shortly after the release of Sonic and the Black Knight, Sega ran a Facebook poll to see what fans wanted Sonic to go to in the third installment of the Sonic Storybook Series, including the old west, a haunted house, etc. Greek mythology won the poll. However, nothing has been announced about the Sonic Storybook Series since.