Photo: A10ml at Japanese Wikipedia / Public domain · Wikimedia Commons
Kosai City
Shizuoka Prefecture · City
Official websiteShizuoka Prefecture page
Kosai City is the westernmost city in Shizuoka Prefecture, spreading from the west shore of Lake Hamana to the Aichi Prefecture border. It has the Arai Barrier, whose Edo-period checkpoint building survives, and the sites of Arai-juku and Shirasuka-juku. It is the birthplace of Toyoda Sakichi, inventor of the automatic loom, and has a memorial hall. It also produces winter cabbage.
Key facts
Source: Statistics Bureau of Japan, 2025 Population Census (population, area and density); area from the Geospatial Information Authority of Japan (GSI), Area Statistics of Prefectures and Municipalities (2025). National ranks are among the 1,741 municipalities, ordered by this site from these values.
Live information
Current weather (observed)
Places to visit
Chosen automatically, most popular first, from landmarks and cultural properties registered in Wikidata (we have not checked whether each is open). Names and descriptions: Wikidata (CC0); photos: Wikimedia Commons (photographer and license under each photo).
Neighboring municipalities
Municipalities sharing a boundary (computed from the National Land Numerical Information administrative boundaries, January 2021).
Other municipalities in Shizuoka Prefecture
The description was written for this site, picking out representative features.