I'm nearly done with the Modification Challenge, but I'm having trouble finding two items: 
 
-Nameless Katana 
-Ancient Chain mail 
 
I'm at the very last chapter and can freely  SPOILER WARNING: Click here to reveal hidden content.

" You can find the nameless katana in the pawn shop when you're playing as Saejima and I think the ancient chain mail can be acquired through the gambling hall or casino prize exchange. Probably gambling hall. "

I've always had good luck playing the evens/odds dice game and betting on whichever side has the least people on it. That's the easiest way to earn some points. The 4-5-6 dice game isn't too bad either but you can lose a lot if you get a bad roll when you're the banker, so it's a bit more risky.

" I've always had good luck playing the evens/odds dice game and betting on whichever side has the least people on it. That's the easiest way to earn some points. The 4-5-6 dice game isn't too bad either but you can lose a lot if you get a bad roll when you're the banker, so it's a bit more risky. "