Matsuyama Children's Book Forest (こども本の森 松山)

The Saka no Ue no Kumo Museum (坂の上の雲ミュージアム), designed by Ando, opened in April 2007. In February 2022, Ando proposed to the city of Matsuyama that a children's “book forest” be added to it. In January 2023 the city and his office signed an agreement on the fitting-out of the room, and in March 2023 the city council voted to accept the gift, which came with conditions. Work began in April 2024, the building was completed in March 2025 and handed over to the city, and the library opened in July 2025.

A call for book donations in autumn 2024 brought in 1,322 volumes given by 86 individuals and organisations.

The idea of the “book forests” is to offer a place where children can meet books freely, enjoy them and learn from them. Ando translated it into space by making the most of the site: the building stands above the water-and-greenery garden on the west side of the museum. Its envelope is made of sloping glass walls that widen upwards; it follows the museum's design code, but in the shape of an ellipse, facing the museum's triangle. The contrast between the two forms is meant to become a new landmark for the “Saka no Ue no Kumo” urban-planning effort.

The building is carried on pilotis so that its main level meets the museum's Library Lounge on the first floor. The oval, single-room reading hall is a free space where children read wherever they like; by connecting it to the museum's public spaces, Ando extends that freedom further.

Inside the room stands a green apple, designed by Ando as a “symbol of youth”, after the poem “Youth” by the American poet Samuel Ullman. He made it with this aim in mind: not the sweet, ripe red apple but the spirit of the green apple, sour and unripe yet full of hope for tomorrow.

The room holds some 4,300 books, mostly picture books and stories. Their selection was led by Haba Yoshitaka (幅允孝), a specialist in choosing books, drawing on interviews with residents, the city's study meetings and the views of experts. The arrangement in nine themes, among them “Our bookshelf for living in the 21st century”, “History is connected” and “From Matsuyama to the world”, reflects the link with the museum and what gives Matsuyama its character, such as haiku and the culture of words.

Books cannot be borrowed. Each person may take one at a time to read in the museum's Library Lounge, but not out of the museum.

The room is entered from the back of the Library Lounge, on the first floor of the Saka no Ue no Kumo Museum. It receives visitors in four 90-minute slots between 9:30 and 17:30, and it empties completely at each change of slot. Each slot has 30 places: 20 are booked online, from fourteen days to the day before, and 10 are taken on the spot, in order of arrival.

When it is busy, reading seats go to children first.