Sending package to the hotel - customs fee

hello
i'll be visiting Japan next month, and i want to buy product from Korea which will be shipped to my hotel in Tokyo. This is expensive product (more than 300$).
I would like to know about the customs process. Does they can send the bill online by email and i can pay also online? Or i must be there personally to pay? I ask because I will be there for only 4 days and I cant deal with this process when i'll be there.
another question is how much the customs fee will be for this product (camera gimbal)?
Thanks!

Here's a place to start:

http://www.customs.go.jp/english/summary/tariff.htm

There are contact numbers at the bottom of the page.

I think your plan is quite risky. There's no guarantee that the item will pass through customs in a timely manner. Also, the method of shipment can also have some bearing on speed, costs, etc. If the seller uses a shipping company, they'll probably go through an agent, like Logistics. If, however, they ship through the post office, customs clearance/payment would be different.

I seriously doubt that the seller will want to ship to someone at a hotel.

Why not just have the item shipped to your home overseas?