During a night time chaji a Kansho is used instead of a Dora to call the guest back to the tea-room.
The kansho came from China as part of the equipage of the scholar's nook created in the suke-shoin (attached desk). It most commonly hangs from ther ceiling of the shoin and its long-handled striker usually hangs on the wall nearby, so the Master can ring for assistance while still seated. A kansho is usually cast of bronze, sometime other metal, using the lost-wax process for small pieces, hard-shell molds for larger ones. Like all Buddhist bells, they are cast without clappers, with the outside decorated with molded or formed details.Its sound is high, sharp and piercing, being considered very YO (yang) to contrast with the darkness, where the gong would be a bit eerie.
Its kanji characters mean "summonings bell" 喚鐘, whereas the characters for dora mean "copper" plus a character used for transliterating, 銅羅 thus indicating its origin outside the Chinese sphere. No matter how many Guests are involved, the kansho is only rung five times, in the same order as the dora, to prevent it being mistaken for a fire bell!