Kamidana

A kamidana is a small Shinto shrine in peoples houses. It literally means kami shelf. Made of plain cypress wood with talismans from local shrines. They are placed high on a wall and resemble a miniature shrine. Offerings to the kami are placed in front of it. Common offerings are rice, salt, and water special occasions sake or food are sometimes placed there. Usually the kamidana enshrines the local kami and perhaps a kami connected to the family in some way. Before worshiping at the Kamidana, it is ritually important to cleanse your hands.

Traditional Japanese Dojos in Japan have kamidana. They are usually located on the North wall if can't be put there then should be on the West wall (so Kamidana's doors open to the South or East). It is very bad luck to put it on the south wall. When entering a dojo it is customary to bow toward the kamidana.

In the Ranma manga and anime the kamidana can be seen in the dojo frequently. It can be seen in the picture above. The kamidana falling down is considered an ill omen. This can be seen in the Ranma manga as well, when Happosai manages to get free from his entrapment in the cave the kamidana falls down.