Sasebo (佐世保市 Sasebo-shi?) Sasebo city is one of the major cities in Nagasaki prefecture. With a population greater than 250,000 Sasebo has a diverse variety for a small city in Japan. It is home the US Naval Base and a bustling shopping area known to the locals as the Arcade. Its location in a rural area gives Sasebo many beautiful sights and things to do. The best of both worlds can be found in Sasebo; if you need a little Western treat or if you are looking for rural Japan, this area has it all.