Danganronpa: Trigger Happy Havoc Anniversary Edition

You can do this after you finish Chapter 1 and go into the school store in the green lit area near the AV room. Getting A ranks on everything, only taking damage once, I was able to get 63 coins. Combined with a little bit of coins I found checking stuff I had 70. You can save right in front of the Monomachine and reload if you get too many duplicates since what you get is random every time even if you reload. Without reloading I had 11 coins, so it just depends on your luck.