There is no warehouse, and there is no backpack for holding props, but there are backpacks with increased grids. You can get them after defeating BOOS. Dongjun's can add 6 grids, and Arnold's can add 7 grids. The grids that can be used in the backpack are limited. There will be two grids at the beginning. Opening the third grid costs 1,000 gold coins. This is not expensive, but opening the fourth grid with points coupons is for sure.