Elementary school (5 Centimeters per Second)

This unnamed elementary school, located in Tokyo, is attended by Takaki Tōno and Akari Shinohara since their 3rd Grade and 4th Grade, respectively, in 5 Centimeters per Second. It is unknown if it is based on a real-life school.

In 5 Centimeters per Second
Like most elementary schools in Japan, this school provides basic education for children from Grade 1 to Grade 6. It also offers optional club activities like choir, and a library for students to read and borrow books.

It doesn't seem to require its students to wear uniforms.