My Pet Shop Is Full of Divine Beasts: You Can't Afford This Dog

In the eyes of ordinary people, this is just a run-down pet shop on the verge of closing. In the protagonist's eyes, it is a room full of mythical beasts from the Classic of Mountains and Seas. By feeding them barbecue, grooming them, and doing other everyday things, he tames the beasts, then turns around and crushes an arrogant tycoon worth tens of billions.