Why have two other parties (distributor/dealer) in the middle when you could work with one?
I wonder how can you work with one if they are in Japan and does not even prepared to sell to the foreigners directly? You can’t, so you need a grey market dealer (the enemy of the manufacturer) between you and the manufacturer or a legit dealer (a friend of the manufacturer) in your country. Up to you, but you can’t buy from the manufacturer even if you really want. This is it, the OP’s post is about Japanese cartridge.
They don’t need your USD in Japan, your paypal that ripping-off the sellers and can block entire account with funds because of the one complain from the cheater/customer, or your American Credit Card. Also most of them don’t even understand a word in English. How can you buy from them with warranty and service ? This is why they do have a distributor and dealer they can trust. Let's face it!