(JP Version)
 
During the game, press Start to go to the Menu Screen. 
Hold R1 and R2, then press...


The hardness of the sword the main character is currently 
equipped with will increase by 1. 
You can use this code as many times as you want until the 
Sword Hardness reaches 5. 
This code will work even if the Sword Hardness is at 0. 
This does not work in the VS Mode.