Hi Shotaro, 

Welcome to the Box Community, I'm happy to help!

Please be informed that this community is primarily intended for English language speakers. If you are able to post your question in English, the community may be better able to assist. Google Translate or other tools may help! If any community members are able to understand and help, it would be greatly appreciated.

Thanks for posting!

If I upgrade from the 15GB Individual plan to the Personal Pro plan and then go back to the Individual plan, will I get 15GB or 10GB?