From what I know, the bigger treasures (400 and 1k style ones) both alternate. You get one and you decide to go again, you'll get the super you didn't get originally.

So for example. You get Hashirama and go for another super rare, Tendo. Go for Ay, get Ay, go again, you'll get Susasuke.

The same applies to GNW Treasure. (But I know it doesn't apply for Edo Tensei treasure, I got Rasa and Rasa for my supers.)

everyone's over there talking about dupe super rares when I don't even have any 700-1200 supers, the only dupe super I have is Rasa ;-;

but I wouldn't mind my first Tendo super being a Tendo, I only need 20 frags for him to be 4*, and I don't have Hashi, so it'll be good regardless