if a wrestler has just touched his foot, or another part of his body, outside the ring. The yobidashi ensure this is clean of any previous marks immediately prior to each bout. A roof resembling that of a Shinto shrine (which has been of the Shinmei-zukuri style since the May 1953 tournament) is suspended above the dohyō, called the tsuriyane. The roof weighs 6.25 tons and is supported by cables that can hold up to 30 tons. Around the tsuriyane hangs a purple banner which is embroidered with the Japan Sumo Association's mon. Prior to the September 1952 tournament the tsuriyane had been supported by columns, but they were removed to allow fans an uninterrupted view of the dohyō. Colored tassels (fusa), which replaced the colored columns, are suspended from the corners. They represent the four seasons and the four spirits of directions: Green – Azure Dragon of the East (青龍), Spring Red – Vermilion Bird of the South (朱雀), Summer White – White Tiger of the West (白虎), Fall Black – Black Tortoise of the North (玄武), Winter The dohyō in training stables is not raised but is otherwise the same as those used in tournaments. One dohyō is standard, although some larger stables have built two. Dohyō matsuri After the dohyō has been built, a ceremony called the dohyō matsuri (ring ceremony) is held. The dohyō matsuri is said to have been introduced by Yoshida Zenzaemon sometime during the Edo period. The Yoshida clan was a prominent gyōji family. The ceremony is done to purify and consecrate the dohyō, while also inviting the kami (Shinto deities) down to watch sumo. The ceremony is led by one of the tategyōji (head referee) along with two other gyōji. The gyōji take the place of Shinto priests. The tategyoji will pray for the safety and well-being of the wrestlers. In the middle of the dohyō a square hole is cut in where the tategyoji will then place inside: torreya nuts, dried chestnuts, salt, washed rice, dried squid or cuttlefish and kombu (seaweed). The tategyoji will then will pour sacred sake into the hole, and around several other places around the dohyō before he will put more clay into the hole. The yobidashi will eventually cover up the hole. The sacred sake is then shared with everyone in attendance. To conclude the ceremony the yobidashi in a procession with taiko drums called