Go to Training Mode to unlock these
These won't work on the first try because you need to complete them on level 3. (level 3 is when there are two solid symbols under the picture of the mission and one transparent symbol) Then you will unlock the item. All of these items will go either to your inventory or the shop in special mode. I'll put Shop or Inv. to confirm which one they go to.
Unlockable How to Unlock
Angle's Kiss - Inv. Rapid Fire
Army Gloves - Inv. Aiming and Accuracy
Comical Bullet - Shop Aiming Reloading and Accuracy
Cradit + 6 - Inv. (so on for the rest) Reloading
Credit Infinite - Shop Aiming Accuracy and Memory
Life + 5 - Inv. Complete all three levels on Aiming
Magazine +4 - Inv. Rapid Fire and Focusing
Mystic Charm - Shop Aiming Rapid Fire and Reloading
Shotgun Bullet - Inv. Rapid Fire and Reloading
Silver Bullet - Shop Rapid Fire Focusing and Judgement
Silver Powder - Shop Rapid Fire Reloading and Focusing
Spirit Brooch - Inv. Aiming and Reloading