Chronicle Mode and Cherry Icon
Enter these codes at the main menu by holding down L1 and R1 and pressing the Triangle button. Tap the button for a "short" press, hold it a little bit for a "long" press, and wait a split second between presses for any *pause* scenarios. The first code enables Chronicle Mode for play without requiring you to have completed Story Mode first; the second simply makes a cherry icon appear at the upper-left corner of the screen.
Code - Effect
Cherry Icon - Short, Short, Short, Long, Long, Long, Short, Short, Short
Chronicle Mode - Long, Short, *pause*, Short, Long, *pause*, Short, Short, Short, *pause*, Short, Short, Long