NoWhen you are transferring 3ds region (with cfw) let say from Japan to Europe can you play online cias and will you be able to update Your system ?
and if you are removing the cfw will the system will stay on Europe region?

If you remove CFW after changing region your console will be a brick. Unless you use donor files from another console that you throw away afterward, or at least make sure never ever goes online.and if you are removing the cfw will the system will stay on Europe region?