If you're active, you should be capable of doing it as you should be able to save 1050 keys from the last rebate.

To sum things up, the seasons will be based on 3 months. Our first season is from March, April, and May which represents SPRING and the next season would be June, July, August represents SUMMER, and so on. Each month will ask you to complete certain tasks for you to complete and some can be a sneak peek in what will happen - ex. edo han will be released this month. Why? Tasks in one month do not carry over to the next month. So that task to get edo han means he will be added before March ends.

Once you complete a tasks you get items (coupons, mysterious frags, and mysterious bags). Mysterious frags are ninjas that are not in the current game and will be added. Some of the mysterious ninjas that were in China instead of here were Guren and Chiraku. There's a few more if you want to check out videos on the China server. The mysterious bags will be able to be opened at the end of the season and you can get power items and frags of those mysterious ninjas.

OR if you want an official instructions, you c*ways click the little book in the event page that is present in every single event.