Kushiro mooring is upriver just before the first bridge on the North bank. There is an outer breakwater and defenses, so the river entrance is calm.
Beware that the ebb tide flows very fast, so preferably moor with bow upstream, but in any case make sure that mooring lines are strong and well positioned.
Seki-San is a helpful local yachtsman who arrived to greet us in the dark with a couple of extra big fenders. He will help you, and took us to a good supermarket. Along the river bank is a hotel with a small laundry that yachts can use, but the driers are small and slow.
Customs and immigration are a five minute walk from the mooring, and are very helpful.