In 3 maybe not so easy steps.
Complete the game. Yep, just like that. Focus on the drinks, buying or drinking, and just skip gacha-machine, you don’t need to waste all your precious money on it.
Find Broker. He will now appear at the entrance of the house.
He can offer one tasty modification for your game:
Take it and go to.
Go into the Mansion and survive long enough to get to one of the secret rooms. Hope you didn’t drink anything costly beforehand, so you will have 10000 to spend in gacha, basically unlocking everything in one go.