All in all, clean reset would occur due to Norikazu's ravings, and Kaede showing up with an elite task force to snuff out the lying darkness plot to kidnap Toturi. Go from there.
I think a clean reset should occur due to Bayushi Shoju realizing that he must ensue that the Hantei line will live forever (thus no "last Hantei" to ever occur) rather than literally turn the current emperor into the last Hantei and thus hilariously missing the whole point of his very own plan.
And if you are interested in a ''what if'' scenario concerning that very story reset, you can always check the Tomorrow's Prophets project.
My problem with TP is that it kinda misses the point: Shoju must act intelligently on his own, and not because some guys from the future drop in and tell him to stop. Him not being stupid should be in his character and not coming from outside sources. His story should be like Toturi's, the hero Rokugan needed but did not deserve.