How do I apply for a local mobile number in Japan?

Hi Christine, welcome to Tokyo! Hope everything is fine with you!

So it is actually not easy for a foreigner to get a mobile number here. Trust me...I've been there lol

First, since you just arrived, you have to get your Japanese residence card and registering as a citizen in Japan. Then, bring your residence card and credit card go to BicCamera or Yodobashi near you. Those are probably the most famous gadget stores in Japan. Just go there and there will be staffs who speak multi-languages to help! You can check all the monthly plan there to find out which is suitable for you!