The urban center of Hikari is located on the alluvial plain of the Shimada River, and on both ends of it lies the Murozumi Coast and Nijigahama Beach, forming part of the Setonaikai National Park.

The area of Hikai was part of an ancient Suō Province and traces of settlements dating to the Yayoi period have been found.

During the Edo Period, the area was part of the holdings of Chōshū Domain and prospered as a port-of-call for the kitamaebune coastal trade.

Following the Meiji restoration, the villages of Mitsui, Shimada, Mii and Asae within Kumage District, Yamaguchi was established with the creation of the modern municipalities system on April 1, 1889.

[5][7] The attacking U.S. aircraft were 156 B-29 bombers[8] of the 40th Bomb Group[9] stationed in Saipan, supported by P-51 Mustangs from Iwo Jima.

The former Hikari Naval Arsenal is now the sites for Nippon Steel Corporation[8] and vaccine manufacturing by Takeda Pharmaceutical Company.

Steel frames that once constituted the structure of the destroyed Hikari Naval Arsenal were used to build the Tsukumo Bridge.

[13] Hikari has a mayor-council form of government with a directly elected mayor and a unicameral city council of 18 members.

In terms of national politics, the city is part of the Yamaguchi 2nd district of the lower house of the Diet of Japan.