Always Check the History Book and Notebook
The story of Valkyria Revolution is structured much like Valkyria Chronicles and presented through a History Book in-game, as two characters in the future try to piece events together. Of course there’s a lengthy main story, but the game also rewards you with a number of optional cutscenes and events to view. Extra fragments in the History Book give you more context on the overall story and world, while the Notebook gives you fun scenes featuring specific party members. Even better, these Notebook scenes can unlock new potentials for your characters.
If you want to properly understand the story of Valkyria Revolution and get more context on events, it’s important that you watch these scenes, not to mention the bonuses your party can get from them.