If you plan to start a business in Japan after graduation, you will need to obtain either the Business Manager (経営管理) status of residence or a Designated Activities (特定活動) status specifically for starting a business.
The requirements differ depending on the type of status, but in either case, significant preparation is necessary—such as creating a detailed, long-term business plan.
Support for applying is available through JETRO Kyoto. Please start by consulting with them directly.
https://www.kyoto-obc.jp/startupvisa/
*Please note that the university is not able to provide assistance for obtaining residence statuses related to starting a business.