Map of Kosai, Japan

Kosai is a city in Shizuoka, Japan, with a population of about 59,770. It lies at 34.7005°N, 137.5225°E. Kosai is about 226 km (140 mi) southwest of Tokyo, the capital. The nearest city on our map is Toyohashi, 15 km to the northwest.

Kosai at a glance

Where is Kosai?

• The 15th largest city in Shizuoka on this site.
• Located in the Northern and Eastern hemispheres.
• Daylight ranges from about 9 h 49 min on the shortest day to 14 h 29 min on the longest day (around 21 December and 21 June).

Cities near Kosai

• Toyohashi — 15 km northwest
• Toyokawa — 17 km northwest
• Hamamatsu — 19 km east
• Shinshiro — 22 km north
• Tahara — 24 km west
• Hamakita — 26 km northeast
• Iwata — 30 km east
• Gamagōri — 30 km northwest
• Fukuroi — 36 km east
• Okazaki — 43 km northwest

Largest cities in Shizuoka

• Hamamatsu — 791,707
• Shizuoka — 693,389
• Fuji — 245,392
• Numazu — 189,486
• Iwata — 166,672
• Fujieda — 145,032
• Fujinomiya — 132,507
• Kakegawa — 117,925
• Mishima — 107,851
• Shimada — 95,719

Largest cities in Japan

• Tokyo — 9,733,276
• Yokohama — 3,777,491
• Osaka — 2,753,862
• Nagoya — 2,332,176
• Sapporo — 1,973,832
• Fukuoka — 1,612,392
• Kawasaki — 1,538,262
• Kobe — 1,525,152
• Kyoto — 1,463,723
• Saitama — 1,324,854

Map of Japan and all its cities →

Sources: place names, coordinates, populations and time zones from GeoNames (CC BY 4.0, data retrieved October 2026). Population figures are the latest values recorded in GeoNames; depending on the country they refer to the city proper, a municipality or a wider urban area, so they can differ from census or metro-area figures. Map © OpenStreetMap contributors.