Fireworks training mode:
Get the top score in story mode to unlock the Fireworks mini-game in training mode.
Magnum:
Successfully complete the Final Chapter in mission mode to unlock a Magnum in story mode.
Shotgun:
Get an "S" rank in all the bonus training missions to unlock a shotgun in story mode.
More credits:
You can gain one additional credit, up to a maximum of twelve, if you lose all your credits in a chapter.
Mission mode Chapter 2:
Successfully complete Guren's Chapter in story mode.
Mission mode Chapter 3:
Successfully complete Gunjo's Chapter in story mode.
Mission mode Chapter 4:
Successfully complete Aoi's Chapter in story mode.
Mission mode Chapter 5:
Successfully complete story mode.
Mission mode Final Chapter:
Successfully complete all chapters in mission mode.