There are many buildings at the Toshougu Shrine in Nikko, and each has its own role. The building from this photo is the Shinyosha (Shed of Portable Shrine), the place where the mikoshi are stored.
There are three mikoshi inside the Shinyosha, for Tokugawa Ieyasu, for Toyotomi Hideyoshi and for Minamoto Yoritomo. Each mikoshi weights 750 kilograms and it is carried by 55 men.
P.S. It is quite cool to learn this information from a… miko, like the people in the photo:
Shinyosha (Shed of Portable Shrine), Toshougu Shrine, Nikko
Yesterday’s Japan Photo: Traditional Japanese sweets