family visa change to student type

Bryan, if your so plans to stay longer, then he should apply for the extension of their student type. However, it depends on whether your son can provide the document to prove that he needs to study for longer time. Usually, his school should give him the admission letter or certificate that he needs to extend his study. If he can provide the document, I think he can do the extension at local entry and exit management bureau.

Do you want to change your family type into student type? If so, you should find a school first and get the admission letter. Then you can try your luck at the bureau mentioned above. If they agree, then you needn't leave to apply for the new one. However, to my knowledge, foreigners in the similar situation are required to exit and apply for a new type.