The largest Japanese island is Honshu, which is 6 letters long. Honshu is the main island of Japan and is home to the country's largest cities, including Tokyo, Osaka, and Nagoya. It is the seventh largest island in the world and is located in the Pacific Ocean. Honshu is known for its mountainous terrain, with Mount Fuji being the most famous peak. The island is also home to many hot springs, shrines, and temples.