The next page of the guide to Judgment will show you how to make a lot of money in the game. Thanks to the money, you can buy a lot of valuable and useful items in the shops found in Kamurocho.
Cash is quite useful in Judgment - you can buy items in stores (including very expensive gifts for the women we date), and spend in the Quickstarter app (this option becomes available later) where you can spend money to fund interesting projects and unlock access to new skills, consumables, etc.
A lot of money can be earned by completing additional cases, which often offer large sums for a fairly short job. Check the current missions regularly and complete them to have access to more money. Another option is to take part in mini-games, some of them, for example, Paradise VR or casino L'Amant allow you to earn a lot of money. Therefore, it is worth visiting entertainment places in Komurocho and take part in tournaments, etc. to make some money.