Thank you for the information and sorry for the late reply, busy days planning the trip!
Hulk - The So-not 12gb option is pretty good, but if activation is in Japanese, it's a problem.
q10 - I'll probably need 2 or 3 of those cards each month, which will be more expensive than Sakura o Mobal.
Peter_Lam The only unlimited data one I saw was for very few days. I'll be in Japan for 90 days.
With Sakura I cannot get their monthly plan as I am not a residence. Their short term plans are not that good.
So now I am either on Mobal.com at Y6000/month for 7 gb + phone number or Freetel (https://www.freetel.jp/prepaid/) as their facebook/whatsapp/line data is unlimited.