To unlock this achievement you past have every page in the story section of Jiminy Cricket's Journal.
When you have a gold Mickey Mouse symbol next to the word story it will be complete.
To fill the Story Journal you need the following:
Sora's Tale I
Sora's Tale II
Sora's Tale III
Sora's Tale IV
Traverse Town
Wonderland
Olympus Coliseum
Agrabah
Halloween Town
Monstro
Atlantica
Neverland
Hollow Bastion
100 Acre Wood
Twilight Town
Destiny Island
Castle Oblivion
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