Report

Journals are recurring mechanisms in the Kingdom Hearts series. While some other games use Jiminy's Journal to record data about characters, enemies, treasures etc, Kingdom Hearts Birth by Sleep, Kingdom Hearts Chain of Memories, Kingdom Hearts 358/2 Days and Kingdom Hearts Re:coded has various different books that are used to record data.

Kingdom Hearts Chain of Memories
During Reverse/Rebirth, Riku uses the D-Reports (D standing for Darkness) to record data.

Kingdom Hearts 358/2 Days
In 358/2 Days, there is much less data recording, with only Roxas' Diary covering events along with the Secret Reports and the Enemy Files detailing enemies.

Kingdom Hearts Birth by Sleep
Aqua, Ventus and Terra hold their own individual Journals to record events. The Trinity Archives holds additional data covering all three stories.

Kingdom Hearts Re:coded
The Debug Reports acts as the Journal for Re:coded. It contains five sections with a percentage representing how much that section is completed (excluding 'Trophies' which features a number out of 30).
 * Trophies: shows achieved trophies and progress to achieving trophies.
 * Collection: shows all Commands, Keyblades and Accessories.
 * Story: summarises the events in each World.
 * Enemy Profiles: shows details for all enemies, including descriptions, drops and how many times an enemy has been defeated.
 * Character Files: contains short biographies for each character.