While the Pokémon Diamond and Pearl remakes contain a few new additions, Nintendo and The Pokémon Company didn’t announce all of them.
One new addition is a hidden tale that has been recently discovered hidden away within the Canalave library. The book is titled “The Seas’ Legend” and was “only recently discovered” which is why it’s only just been added to the game.
Here is the story in full:
Once upon a time in the East Sea, there was a Pokémon known as the prince. A brave human asked Pokémon living in the sea to let them see the prince. Mantyke, Buizel, and a Quilfish with huge spikes acknowledged the human’s bravery and joined them. Together, they set off in a boat over the sunset-streaked sea, sailing through the ocean gate stretched over the waves. News of this reached the ears of the prince, who went to meet the brave little party at the Seaside Hollow.
There was an embargo for Pokémon Brilliant Diamond and Shining Pearl that prevented the media from revealing or discussing the contents of the books in the Conalave library. Confirming that the new books is some kind of teaser.
There is no Seaside Hollow in the main series, but “Prince” is a name that “Manaphy” would use in the Pokémon Ranger and the Temple of Sea film.