First-class national universities include Tokyo University, Kyoto University, Hokkaido University, Nagoya University, Osaka University, Kyushu University, Tohoku University, Tsukuba University and hitotsubashi university.

I can provide you with the admission conditions of Nagoya University for your reference.

Studying in Japan requires the following results.

Department of Law, Department of Education, Department of Economics and Department of Literature: 220 points or more in Japanese, and 265 points or more in mathematics+comprehensive subjects.

Ministry of Engineering, Ministry of Agriculture, Ministry of Science: above 220 Japanese, above 265 math and science.

Department of Medicine: 360 or above in Japanese and 320 or above in mathematics and physics.

The requirements for English are as follows

Departments outside the medical department require TOEFL IBT 39 or above. The requirement of the medical department is TOEFL IBT 90 or above.

These are just the requirements for applying for a university. Then the school has its own assessment methods. Written test, interview, etc.

I hope it helps you.

Feel free to consult if you have any questions.