This fast population growth reflects the low unemployment rate, as well as affordable housing close to Nagoya.

During World War II, the July 19, 1945 Bombing of Okazaki killed over 200 people and destroyed most of the city center.

Although Okazaki was the location of an Imperial Japanese Navy airfield, military installations were not damaged in the attack.

The former towns of Iwazu, Fukuoka, and Yahagi, and the villages of Motojuku, Yamanaka, Kawai, Fujikawa, and Ryugai were all merged into Okazaki.

Okazaki has a mayor-council form of government with a directly elected mayor and a unicameral city legislature of 37 members.

In terms of national politics, the city is part of Aichi District 12 of the lower house of the Diet of Japan.

Captured by the Matsudaira clan in 1524 (and probably relocated from the other side of the river), the castle remains associated with Tokugawa Ieyasu, even though the latter transferred to Edo in 1590.

During the Edo period it served as the seat of the Okazaki Domain and dominated the city until the Meiji Restoration.

A large fireworks festival, which people from all over Japan come to see, is held annually on the first Saturday in August in the area surrounding Okazaki Castle.

Located 8 chō (hatchō, or approximately 900m) west of Okazaki Castle near the Yahagi river, there are two 8-cho miso companies — Maruya from 1337[12] and Kakukyu.

A 2006 NHK morning drama serial, Junjo Kirari (Sparkling Innocence), was largely filmed in and around the Hatchō miso grounds.

Hatchō miso's health properties are considered so great that it was donated to Chernobyl's citizens following the disaster, to help prevent and treat radiation sickness.

The main hall is from the Kamakura period and is the location of a fire festival held each February on the closest Saturday to the lunar calendar New Year.

Cognitively Mikawa-ben and modern contemporary Japanese are extremely close, in part due to the influence of the Tokugawa shogunate and accidents of history.