Whale... well I do purchase almost every choose your rainbow deal and some dressblooms but never bother with the rest especially buying gem due to my terrible luck. Would call myself dolphin at most I guess.
This was the team I use to cleared the latest kodaibana. Saffron, Epidendrum, Dogwood, Shirotaegiku (Christmas ver.), and Stock are lucky draw. The rest are choosing deal.
The key is to spread around some firepower a bit. Don't simply cluster the best girls in one team.