Final Fantasy XIII-2 is more than just a follow-up to the original FF13. It offers everything from capture-able monsters to character customization well beyond anything the first game had to offer.
In addition to various forms of customization, you can equip your characters with a variety of armaments and weapons—some of which are 'secret'. These secret weapons are a lot more difficult to acquire than regular ones and require that you perform certain actions in order to get them.
Here's a small guide written by Japanese gamer Hsypersakura, who also produced the video above:
Step 1 :
First purchase "CHAOS CRYSTAL" on casino.
(10,000 Coins for Default Exchange)
(7,500 Coins if fragment skill "SHOP DISCOUNT" is ON)
Step 2 :
Visit & Talk to hope and give him the "CHAOS CRYSTAL".
Step 3 :
Talk to the woman in information counter to receive a special gift. (You can only choose 1 Weapon at This Time)
Step 4 :
Go to Casino again to purchase (Exchange Coin) another weapon.