Kai, Yamanashi

This article is about the city in Yamanashi Prefecture, Japan. For other uses, see Kai.

Kai (甲斐市, Kai-shi) is a city located in Yamanashi Prefecture, Japan. As of 31 December 2021^[update], the city had an estimated population of 73,626,^[1] and a population density of 1,100 persons per km². The total area of the city is 71.95 square kilometres (27.78 sq mi).

Kai 甲斐市
City
Kai City Hall
Flag Emblem
Location of Kai in Yamanashi Prefecture
Kai
Coordinates: 35°39′38.9″N 138°30′56.8″E
Country	Japan
Region	Chūbu (Tōkai)
Prefecture	Yamanashi Prefecture
Area
• Total	71.95 km2 (27.78 sq mi)
Population  (December 31, 2021)
• Total	73,626
• Density	1,000/km2 (2,700/sq mi)
Time zone	UTC+9 (Japan Standard Time)
City symbols
• Tree	Zelkova serrata
• Flower	Sakura
Phone number	055-276-2111
Address	2610 Shinohara, Kai-shi, Yamanashi 400-0395
Website	Official website

Shingen Embankment and Kamanashi River

Geography

Kai is located in central Yamanashi Prefecture, orientated north-south along the banks of the Fuji River.

Surrounding municipalities

Yamanashi Prefecture

• Hokuto
• Kōfu
• Minami-Alps
• Nirasaki
• Shōwa

Climate

The city has a climate characterized by hot and humid summers, and relatively mild winters (Köppen climate classification Cfa). The average annual temperature in Kai is 14.3 °C. The average annual rainfall is 1240 mm with September as the wettest month. The temperatures are highest on average in August, at around 26.7 °C, and lowest in January, at around 2.4 °C.^[2]

Demographics

Per Japanese census data,^[3] the population of Kai more than tripled between 1960 and 2000 and has grown at a slower pace since.

Historical population

Year	Pop.	±%
1940	17,777	—
1950	24,497	+37.8%
1960	22,951	−6.3%
1970	27,075	+18.0%
1980	45,337	+67.4%
1990	60,765	+34.0%
2000	71,706	+18.0%
2010	73,807	+2.9%
2020	75,313	+2.0%

History

The area of present day Kai was part of ancient Kai Province and have numerous Jomon period ruins. During the Sengoku period, warlord Takeda Shingen built embankments on the Kamanashi River for flood control and to open up new rice lands. During the Edo period, all of Kai Province was tenryō territory under direct control of the Tokugawa shogunate.

The city of Kai was established on September 1, 2004, from the merger of the town of Futaba (from Kitakoma District), and the towns of Ryūō and Shikishima (both from Nakakoma District).^[4] It takes its name from the old name for Yamanashi Prefecture, Kai Province.

Government

Kai has a mayor-council form of government with a directly elected mayor and a unicameral city legislature of 19 members.

Education

Kai has eleven public elementary schools and five public middle schools operated by the city government and one public high school operated by the Yamanashi Prefectural Board of Education.

Transportation

Railway

• Central Japan Railway Company - Chūō Main Line
  • Ryūō - Shiozaki

Highway

• Chūō Expressway
• Chūbu-Ōdan Expressway
• National Route 20
• National Route 52

Sister cities

• Keokuk, Iowa, United States^[5]

Notable people

• Youichi Imamura – professional racecar driver
• Shin Nakagomi – professional baseball player
• Karin Ogino – former idol