The story behind Zest is that you, Zefaa,woke up at a desert after you have been knocked unconscious. You realized that you have lost all of your memory except you first name. Since there are no one around the desert, you decide to find a place to rest and begin the search of your own identity. From here on, you will choose one of the four paths and begin your quest for your past.

[From Anime Densetsu]