Thank you for your reply.
Regarding to your request,
1. Invoice is a "must" document when sending by EMS, and therefore it is indispensable.
Other forwarders also require it as a "must" document.
2. The shipping charge written on the EMS voucher is filled in by the post office official. We cannot write it.
However, we can describe on the EMS voucher and on an Invoice mentioned 1 above as 4,000 yen Matcha.
3. We can send foil bags without label, but it makes hard to distinguish products when sending several types in one parcel.
I'd appreciate your consideration.