How to get student visa for medicine

As a student how much money that I need to proof my bank accounts?Is that definetely needed or can I get a dependent visa because my boyfriend works in japan.and what are the qualifitions to get visa to study medicine in japanese university?

You need to be married to be eligible for dependent status.

Medical studies is a big commitment - six years of study.
Have you looked into the qualifications to be accepted into a university in Japan to study medicine, rather than for visa? Once you are accepted, the university will help you with the visa application.

You cannot apply for depended visa since you mention Boyfriend which means you are not married.
You can apply for a study visa if you are planning to go study and find the suitable school.

First step would be to be accepted by a university.

Otherwise all the visa stuff etc doesn't matter.

Fluent in Japanese? Both verbal and written? Otherwise, good luck.

You will need student visa - you are not eligible for dependent visa even if engaged to be married/fiance. Need to be married for that route to work.