tōsu 東司

Also read tōshi. Originally tōsu was the god of the latrine who was also called fujō kongō 不浄金剛, or dirty water kongō. A toilet, latrine or lavatory at a Zen temple. The tōsu was also called tōjo 東序 or tōjō 東浄 meaning the lavatory for monks living on the east side of temple grounds. For the group of monks living on the west side of the temple grounds, the latrine was called saijō 西浄. The westside toilet was also called seijō 西浄, and eventually became contracted to setchin 雪隠 (snow hidden), the common name used for the toilets in a tea ceremony garden *chaniwa 茶庭. See *sunasetchin 砂雪隠 (sand toilet).

The lavatories were situated diagonally to the left and right of the bathhouse *ōyuya 大湯屋. The tōsu was at the east right front of the grounds facing the main gate, while the saijō was at the west, left front of the grounds also facing the gate. The priests of highest status used the tōsu, and lower level administrators used the saijō. Eventually, as tradition has it, the separate latrines were combined into one and called Tōsu. 

Only two are extant at Zen temples. These are: Tōfukuji 東福寺 Tōsu (early 15th century) in Kyoto. It is 7 × 4 bays (27.07 m × 10.36 m) and has a gable roof *kirizuma-zukuri 切妻造 covered with tile *hongawarabuki 本瓦葺. Its only entrance is on the north gable end. The interior is now lacking all its original fixtures. The other tōsu is at the Zen temple called Shūon'an 酬恩庵 (1653) in Kyoto. It is 2 × 2 bays (4 m × 3 m) and also has a gable roof that is covered with pantile *sangawarabuki 桟瓦葺. At Rinnōji Taiyūin 輪王寺大猷院, there is a toilet called Reibyō Saijō 霊廟西浄 (1653) in Tochigi Prefecture. It is 5 × 2 bays (9.10 m × 3.64 m), and has a gable roof. It has an entrance on the gable end. The roof is copper-covered to simulate tile, dōbanbuki 銅板葺.