After entering Japan, can I enter and exit Japan by using my student visa?

You can leave and re-enter Japan with a "re-entry permit". There are 2 different kinds depending on your situation, so please check the website on immigration
matters.

Application for Re-entry Permit (Immigration Services Agency of Japan)

Start of a new residency management system (Immigration Bureau of Japan)

If you couldn't find an answer to your question or concern, you may inquire us through the questionnaire form we shared when sending you the Letter of Acceptance or the questionnaire form shared during the orientation. If you are not applicable to these, inquire from here.