Originally Posted by HungryHunter

stupid question are Crystals ingame currency like Flower Knight Girls' Flower Gem and Aigis's SC

Yes.

On a side note, I like to use Roche, the gunner from the Mancha, for grinding. Great Dark-Neutral element with an AoE skillset to clear out hoards of mobs quickly. Stick the puss in some boots and you can autorun your way through the whole game.

If you're lucky enough to get and level her up, Lune can do this job just as well, or even better.

Also, COOKIES! Bake some cookies; you'll get the egg-currency faster that way.