After reaching six paths for the first time, the next month you will receive rewards based on the rank you have. Before you only got ninja student rewards since you didn't get six paths before the end of the month. After January ends, you will get rewards based on six paths rank then the rank will reset for february. You don't have to get super kage just to get rewards based on your rank as Shyrke is trying to point out what happens now.
Rank only resets per month if you get six paths so if you can onky get to kage for february, then you get to keep that rank and get rewards for kage.