Don't get discouraged, the odds are indeed sucky, but it'll happen sometime. i've been playing since day 1 as a free player and I believe i've done 6 or 7 10+1 pulls so far and I had never got a single 5* until my last pull where I got 3 at once!
So I guess the lesson is: don't get your hopes up everytime you're about to draw from the premim gacha but keep playing and trying and eventually it'll happen. Also, note that buying gems is a very poor investment since it won't garner you anything for sure, so I'd tell you to not waste your money.

Originally Posted by zathosi

I am a premium player, but recently, after many horrible gacha rolls, I have decided to stop buying gems for this game. With all the back-to-back events that we have, we will have a full harem (um...army) of 5* girls in maybe 5-6 months. This will make 93,5% of rolls from the premium gacha a complete waste and garbage.

^ this