>>715366081
Kyoto Racecourse and Straightaway Recovery I only bought with the bonuses from winning the finale. Getting perfect compatibility with the legacies was really important because it gave her 50 stamina right from the start and another 50 for both of the inspiration moments. Raising her to Potential 3 also helps a lot because the navigation skills innate to her let you not train power as much as you would need to otherwise. I also bought the two levels of firm conditions right before the finale after confirming that it was firm ground.
Luck is also a big factor, I only had one negative event in that run and Night Owl only took the one turn to cure.