Where to buy boxes/packing materials

I will be traveling to Japan this week, and will most likely have to mail a few things back to the US. I have been told that Japanese post offices do not sell things like boxes and packing materials to send medium sized items with. If this is the case, would anyone know where I could purchase these things, and an example of a name of a store? Thank you very much for any help!

Stiltzkin,

Post Offices certainly sell boxes for sending parcels of all sizes. If you want something even larger, then try a "home center" (DIY store) or somewhere like Tokyu Hands in Tokyo.

If you want something larger, most supermarkets give away used boxes for free. They usually have them stocked right outside the cashier for customers to pick up. You can use used magazines and newspaper to wrap fragile material.