Originally Posted by Unregistered

What is Gacha?

One of the core mechanic of this game and it's main selling point nonetheless is rolling a slot machine to get and collect girls.

The gacha is a mechanism by which money is made by the developer but with the participation bar (in the form of FGs) set sufficiently enough to deny accusations of "pay 2 win".

It's not really a core mechanic of the gameplay though.