yes it does separate these two islands in japan
Osaka, Mount Fuji, and Hiroshima are in Japan. The Suo Sea is located near Hiroshima in the Seto Inland Sea, which lies between Honshu, Shikoku, and Kyushu islands in Japan.
Inland Sea, is the body of water separating Honshū, Shikoku, and Kyūshū, three of the main islands of Japan. It serves as an international waterway, connecting the Pacific Ocean to the Sea of Japan.
it has 4 Japan has 4 MAIN islands, (Honshu, Hokkaido, Kyushu, and Shikoku) but Japan actually has over 1000 islands. Only around 30 or more of those islands have citizens. Other islands include Okinawa, Bonin islands, and the Ryuku Islands
It Provides Food and Trade Routes
the inland sea
Honshu is the main and the largest island in Japan. Located in the south of Hokkaidō across the Tsugaru Strait, north of Shikoku across the Inland Sea, and northeast of Kyūshū across the Kanmon Strait.
The same as most nations use the waterways; transportation of goods & trade.
The largest city in Shikoku is Takamatsu, which is located in Kagawa Prefecture. It serves as a key economic and cultural hub for the region, known for its beautiful parks, historical sites, and as a gateway to the Seto Inland Sea. Takamatsu is also famous for its udon noodles and has a vibrant port that connects it to other parts of Japan.
Living in Shikoku offers a relaxed lifestyle with beautiful natural scenery, including mountains and coastline. The region is known for its traditional culture, historic temples, and delicious local cuisine. Residents can enjoy outdoor activities like hiking, cycling, and onsen visits in a quieter, more rural setting compared to other parts of Japan.
To the south, Japan is bordered by the East China Sea and the Philippine Sea. The East China Sea lies between Japan and the Asian continent, while the Philippine Sea is located to the southeast of Japan, separating it from the Philippines. These waters play significant roles in trade and regional maritime activities.
Red Sea (Cataract near the peninsula)