Ōtsu

Ōtsu serves as the capital of Shiga Prefecture in Japan. As of October 2021, its estimated population was 343,991, living in 153,458 households, with a population density of 740 people per square kilometer. The city covers an area of 464.51 square kilometers.

Settlement in the area dates back to at least the Yayoi period, when it was part of ancient Ōmi Province. Ōtsu was a major hub for inland water transport on Lake Biwa and appears in the Man'yōshū under the names Shiga no Ōwada and Shigatsu. It also sat at the crossroads of key land routes—the Tōkaidō and Nakasendō—linking the eastern provinces to Japan’s ancient capitals, as well as the Hokurikudō, which connected Kyoto to northern Honshu. For a brief period from 667 to 672, Emperor Tenji’s Ōmi Ōtsu Palace made the city the nation’s capital. After the Jinshin War, it was renamed Furutsu, meaning "old port." When Heian-kyō (modern Kyoto) was established nearby in 794, the city reclaimed the name Ōtsu, meaning "big port," and resumed its role as a key transit point and satellite town.

During the Edo period, Ōtsu flourished due to its Lake Biwa port and its status as Ōtsu-juku, a major post station on the Tōkaidō and Nakasendō highways. The Tokugawa shogunate governed the city directly, valuing its strategic location and its importance for travel and trade. Nearby, the Zeze Domain was based in the castle town of Zeze, while the smaller Katada Domain controlled the northern part of present-day Ōtsu from 1698 to 1826.

The Meiji Restoration in 1868 brought a new central government in Tokyo and the abolition of the han system. That same year, part of old Ōmi Province became Ōtsu Prefecture. Several smaller prefectures merged into it by 1871, and on January 1, 1872, it became part of what is now Shiga Prefecture, with Ōtsu named the prefectural capital. The modern town of Ōtsu was established on April 1, 1889, under the new municipal system, and it gained city status on October 1, 1898.

On May 11, 1891, the Ōtsu incident occurred: Tsarevich Nicholas Alexandrovich of Russia (later Tsar Nicholas II) was attacked with a saber by Tsuda Sanzō, an escort policeman, while returning to Kyoto from Lake Biwa. Nicholas survived, but the event strained Japanese-Russian relations. Locals briefly considered renaming the city to escape the stigma, but the idea was dropped.

The Lake Biwa Canal, stretching 8.7 kilometers between Ōtsu and Kyoto, was built in the 1890s and expanded during the Taishō period. It connected the cities, supported water and passenger transport, and provided electricity for Japan’s first streetcar services. The canal was designated a Historic Site in 1996.

Ōtsu expanded through annexations: the village of Shiga in 1932; the towns of Zeze and Ishiyama in 1933; the villages of Sakamoto, Ogoto, Sakashita-honmachi, Oishi, and Shimoda-kamimura in 1951; and the towns of Katata and Seta in 1967. On March 20, 2006, the town of Shiga (from Shiga District) was merged into Ōtsu.

Census data shows steady population growth over the past century.

Geographically, Ōtsu sits on the southern and western shores of Lake Biwa, occupying most of southwestern Shiga Prefecture. The city is L-shaped, stretching along the lake’s southwest shore. Its terrain ranges from densely populated lowlands near the lake to sparsely populated hills and mountains to the west (the Hira Mountains and Mount Hiei) and south. Mount Hiei forms much of the border with Kyoto.

Neighboring municipalities include Kyoto, Uji, and Ujitawara in Kyoto Prefecture, and Kōka, Kusatsu, Moriyama (via the Lake Biwa Bridge), Rittō, and Takashima in Shiga Prefecture.

Ōtsu has a humid subtropical climate, with warm summers and cool winters that see little to no snowfall. The average annual temperature is 13.8°C, and average annual rainfall is 1,430 mm, with September the wettest month. August is the warmest month, averaging 25.8°C, while January is the coolest, at 2.3°C.

The city operates under a mayor-council system, with a directly elected mayor and a 38-member city council serving four-year terms. Ōtsu sends two members to the Shiga Prefectural Assembly and is part of Shiga 1st district for the lower house of the national Diet. City hall is in the central Goryō-chō district. Kenji Sato became the 24th mayor in 2020.

Historically, Ōtsu was known for products like Ōtsu-e, a folk drawing sold to travelers in the Edo period; the Ōtsu soroban, an abacus widely used from the early 17th century; Zeze-yaki and Konan-yaki ceramics; and Zeze-cha, the first Japanese tea exported to the United States. Though not an agricultural center, the city produces edible chrysanthemums, used in tempura and as sashimi decorations.

Educational institutions include Biwako Seikei Sport College, Seian University of Art and Design, and Shiga Junior College.