Toyosaka Municipal Library (新潟市立豊栄図書館)

The library was commissioned by the city of Toyosaka, now part of Niigata. It was funded in part by a subsidy of 434 million yen tied to the construction of the fourth series of the Tohoku Electric Power thermal power plant, and its opening on 1 November 2000 was one of the events marking the city's thirtieth anniversary.

The former mayor recounts how Ando came to the project. Invited in 1994 as a panellist to a seminar on urban development and environmental art in Osaka, he heard Ando there as the keynote speaker. In June 1997 Ando visited Toyosaka; looking at the trees left on the site of a former primary school, he said: "Please, let me do it." The mayor replied that the total budget was 1.2 billion yen and that the design fee could only be the ordinary fee provided for in that budget.

A construction committee of fifteen members, eight citizens and seven municipal staff, was set up in September 1997. Ando gave a lecture in October; the committee submitted its proposed brief to the mayor in December; in March 1998 Ando presented his design to the committee. After the presentation, committee members made proposals and Ando revised the design to take the users' point of view into account. Construction ran from June 1999 to October 2000.

In March 2005 the town's merger with Niigata gave the library its present name as a Niigata city library. The nearby junior high school was also designed by Ando.

The building is reinforced concrete on two levels. The site measures 4,323 m2, the building footprint 1,387 m2 and the floor area 2,145 m2 (2,082 m2 for the main building and 63 m2 for a plant building). Shelving capacity is 225,000 volumes.

The design rests on two figures, the square and the circle. The square volume opens with a void joining the ground and first floors. The children's room is circular, with its own void, and its walls carry shelves. The plan is laid out so that visitors move from one space to the next and come across a wide range of books and documents.

The concrete is left exposed. Its execution was prepared by tests on the raw materials and by a small trial building put up on the site; the result is concrete as smooth as a mirror, with sharp straight and curved lines. The shelves and carrels are made of plywood, whose wood gives warmth. The shelves are square, with a thick vertical board every 90 cm, a form also found in the International Library of Children's Literature in Tokyo, the Shiba Ryōtarō Memorial Museum in Osaka and the Watanabe Junichi Museum of Literature in Sapporo.

The entrance is surrounded by greenery. An oak was planted as the emblem tree.

The library has general collections, a children's book room, a storytelling room, a teens' corner, a collection on the region and local government, an audio and video corner, a reference corner, a lounge corner, a reading-aloud and recording room, a volunteers' room, a café and closed-access stacks. It has 218 reading seats. Themed displays are renewed in a circular corner, a general themed corner and a teens' corner.

Volunteer groups support the library, including a support group that was active even before the opening and groups that read aloud to children. In April 2004 the Minister of Education honoured it as an exemplary library for promoting reading among children.

The library is open from 10:00 to 19:00 Monday to Thursday and on Saturday, and from 10:00 to 17:00 on Sunday and public holidays. It is closed on Fridays, on the first Wednesday of the month (shelf-sorting day), from 29 December to 3 January and during the annual stocktaking period, which lasts ten days at most.

The library is in Kita Ward, Niigata, a ten-minute walk from Toyosaka Station. A car park of 110 spaces is shared with the ward office and other neighbouring facilities.