The city of Nagato is located in northwestern Yamaguchi Prefecture. It is a popular tourist destination with a population of 25,000. Besides sightseeing, its major industries include fishing and marine-products processing. Its most famous marine product is kamaboko, or salty steamed fish-paste cake.

Just off the northern shore of central Nagato is the island of Omi, connected to the mainland by the Omi Ohashi (Bridge). Kayoi Middle School is located on the eastern tip of the island.

Omi is a small island measuring 8.5 kilometers east to west and 3.5 kilometers north to south with an area of 14.5 square kilometers. It forms the core of the Kita Nagato Coast Quasi-National Park and is famous for its scenic beauty. The island's northern shore has steep cliffs, formed by erosion from winds and waves, while the southern sections feature picturesque Lake Omi and calm and lovely inlets.