Buying a car in Japan

Moving to Japan for school next year and I’m trying to find out how to buy a car and what might stop me from doing so. Basically what are the requirements for purchasing a cheap second hand Kei car in Japan. Do I need proof of residency, Hanko stamp, proof that I have a parking spot, or anything else that might make it impossible? I’m sure regulations vary somewhat, but I can’t find any decent answers by simply googling.