The Nemuro Strait is the narrow stretch of sea between the eastern end of Hokkaido and Kunashir, the southernmost large island of the Kuril chain, and the coast road beside it is a good place to end a ride. South of Rausu, the road follows the shore with the water on one side and low, grassy, windswept country on the other, and the view across the strait is of a long volcanic island that is plainly visible and, for most visitors, entirely out of reach. Kunashir is administered by Russia, while Japan still claims it, so the sea here has a quiet political weight.
It is also a rich piece of water. The strait is cold and nutrient-heavy, with kelp beds, salmon runs, and fishing fleets that work out of small harbours. Sea fog is common in summer, rolling in from the cold current and wrapping the coast in white, then lifting by midday to reveal a bright, hard blue. In winter drift ice can reach the shore, and a few weeks later the sea breaks free again. Birds are everywhere, from gulls and cormorants to the great eagles of the region.
Riding along the strait is simple and open. The road is wide, the surface is good, and the bends are mild, with long views and few trees. It is a place to relax after the mountain sections, with a sea breeze and occasional farm vehicles as the only company. Wind can be stiff, so watch for gusts on exposed sections, and the temperature can drop abruptly when fog arrives, which is a reason to carry an extra layer even in July.
The nearest town of any size is Shibetsu, about thirty-four kilometres south, with around twenty thousand people and the usual choice of fuel, food and beds, and it is the sensible place to plan the end of the day. Further south, the long sand spit of the Notsuke Peninsula reaches out into the water, and its shallow lagoon draws birds in large numbers. The local fish and dairy products are excellent, so look for fresh salmon, scallops and ice cream before you turn for home.