Like Akamu said, i also stomped by the difficulty of gaining coupon, yeah you can get it by ninetail boss battle, tree upgrade and some completion of story and elite instance mod ... but it stop at that. At least give us a daily resouce of gaining it ... and yeah the gaara recharge event is fair and was the only one that make me recharge in game lol.

Long story short - gimme mah coupon bro.