In about a week I completed the game, except 1 S-rank Mission. getting max money is heck a easy. Just got to infinite missions. Personally, I take the mission that has a reward 30,000+ You wanna start on this when you characters are all max cuz it will be pointless. You can also do listed mission, A-rank perhaps. Then you'll simultaneously gain money and experience points. One way to get many exp points is Chakra Release, I mean I can get up to 700 EXP points on the character and 70 exp POINTS for every one.