Isumi district

Isumi is an administrative district on the eastern coast of Chiba Prefecture that includes the towns of Otaki and Onjuku. The area spreads across roughly 155 square kilometers and is shaped by the Isumi River, which flows through the region.

The area was formally established as a district in 1878 and took its name from the Isumi River, mentioned in records from the Nara period centuries earlier. The region has served as an important hub for trade and fishing over many generations.

Fishing traditions shape daily life here, with many residents building their communities around coastal catch and marine livelihoods. In the harbors, you notice how work patterns follow the tides and seasons, reflecting ways of living passed down through generations.

The district sits roughly 70 kilometers from Tokyo and connects through the Sotobō Line with regular train services to the capital. Spring and autumn offer the most comfortable visiting conditions, as summer brings crowds to the beaches and winter weather can be unpredictable.

Positioned on the Bōsō Peninsula, the area has direct access to Pacific fishing grounds, making it one of the region's primary fishing centers. The location supports thriving marine industries that are less visible to casual visitors but deeply rooted in local commerce.

Location: Chiba Prefecture

Inception: November 2, 1878

Website: http://isumi-kouiki.com

GPS coordinates: 35.23117,140.23361

Latest update: December 7, 2025 10:01