I haven't use may stone yet. I'll wait to see if new girls will be added (I don't think but I will wait just to be sure).

The thunder kunai girl is Japanese (Water) Iris and she is a really nice girl (even if her moving pest ability is a bit useless). She was in one of my main team on Nutaku and I really like her. I guess I'll pick her with all my unused 2015 stones.