I found b-mobile S offer for 7GB/ 25days/ 2980yen トップページ|b-mobile Sプリペイド on bmobile website
Is this prepaid SIM available in any stores, or only online? is there a website in English for this offer, my Japanese is not good enough to read all details
Another offer is 7GB/ 1 month/ 3500yen+tax
same question, can i buy it at an airport or yodobashi like stores?
Alternately can you point me to an offer that is minimum 24days and is under 3500yen? 2GB data is enough for me.
I’m not sure, but you could check the stores when you arrive, or - and this might be easier - just pick up a travel SIM from one of the vending machines before you leave the airport. You might need to increase your budget a little, though.