One way to make money fast is by taking on special quests and completing them promptly for rewards. Also, keep an eye on market trends to know when to sell your items at the best prices.
To make money fast in Story of Seasons, try to upgrade your tools and equipment. It'll help you work more efficiently and increase your output. Additionally, look out for rare items and sell them for a profit.
One way is to invest in the stock market in the game. Keep an eye on the news and the businesses' performance to make smart choices. Also, completing side quests and challenges can give you decent payouts.