This is for completing a Course in Arcade mode with an S rank. It isnt too difficult. Just use Snake Way Course. The first two fights can be completed with almost no damage. Final one may be a bit difficult.
You rank will be determined by How much Health you have left, how much time it took you to win, Finish Bonus which is basically how you KO the opponent(Destructive finish or Ultimate attack) and Technical Bonus which will be you fighting tactics. Im guessing Combos and move varieties.