I will be traveling to Tokyo this month for the World Kendo Championship. After the competition I intend to continue traveling through Japan, and I would rather not bring the Kendo equipment with me as I have no further plans to practice. The easiest solution would be sending it home.
That means sending a large package (~20 kg) internationally from Tokyo (through surface mail).
Can I do this at any post office or is this service only offered at specific locations?
Specifically, I am interested in this post office. I wasn't able to find anything on the page about international mail or packages (though I used Google Translate, so it might be there anyway).