In the past of Japan, there were tea shops along main roads. Benches were put in the open air at a fine day, and travelers took a rest there.
One day, an antique dealer who is "Gintoki" came to a tea shop and took a seat. Watching scenery idly, he took notice of a plate on which a cat ate her food.
He is surprised and says to himself,
"What! That's 'Tohyako' from Hokaido! It's the superb piece which would be sold for 300 ryous (A currency denomination during the Edo period. 300 ryous are huge, 100 - 300 thousands dollars or so nowadays.) at least."
And he considered how to get it. Fortunately, the old master of the tea shop "Shinpachi" did not know that Gintoki is an antique dealer. Gintoki took the cat up in his arms and called the master Shimpachi.
"Oh, what a pretty cat! What is her name?"
"This cat? Her name is Kagura,"
" Oh, I'm sorry. I've got something to ask you, would you please give me this cat? In fact I had missed my cat before I set out on a trip, and my wife feels lonely. I will pay 3 ryous, so please give her to me."
"3 ryous! It's no problem to give you the cat because I had many other cats, but 3 ryous are too many"
"It's OK. Hey, here are 3 ryous."
He payed.
"...And I will get this plate, too. 'Cos it is said that a cat doesn't eat on the plate which she doesn't get used to."
"No."
"Why?"
"Never."
"I can't understand. It's a mere plate, isn't it?"
Shinpachi laughed.
"I will tell you the reason because you don't seem to know the value of the plate. It is called 'Tohyako' from Hokkaido and very worthy. It is the superb piece which would be sold for 300 ryous at least."
"Damn you! You know that. ...Ouch! The cat clawed my face! That's why I hate cats. ...OK, but why do you feed cats on such an expensive plate?"
Shinpachi snickers,
"Because if I feed cats with it outside, sometimes a cat is sold for 3 ryous."