Money is used to buy food and items such as balloons, masks etc. There are easy ways to earn money
The first way to get money is to take the 500 thousand yen worth of gold in the tax office chief’s office. Defeat the tax office chief with a shotgun then take the gold in the secret room behind the bookshelf.
The second way is to complete the mission. The money obtained from trophy prizes is very much. (Hundreds of thousands)
The third way to get money is to take the money that is scattered in the city of Sakura.
Work in a repair shop go to the grocery shop (repairing cars) then ask the person in the reapir shop for a job.
You can also get a lot of money from momogumi inside. Beat the people in it and then take the money. Everyone gives you 1000 yen. Usually I get around 30,000 from momogumi inside.
Last, ask friends for money. The trick is, you chat with other people then select give me some money
https://temannyantai.com/sakura-school-simulator-location-of-money/