It doesn't matter. You should contact the tutor first to see if any students want you. After all, not every tutor is willing to transfer professional students. Grades are not a problem. Graduate students in Japan don't pay much attention to grades. Of course, a higher level is better, but it's ok to get by, and grades don't play a decisive role. In addition, you need an English score, TOEFL TOEFL, and TOEFL is recommended. Japanese universities generally recognize TOEFL scores. If you want to go to graduate school, you need to study for six months to one year. This is not a domestic concept. It's equivalent to a preparatory student, and then you can prepare for the exam and enter the university to study as a monk, which is what we understand as a master student.