Broken key repair of book return post lock

"I want you to remove the broken key."

What is a return post?I arrived at the scene while thinking.There was a mailbox at the entrance of a certain library in Tokyo.

(The key is broken, isn't it? It's Takigen's #400 key.)

I searched the office and met the person in charge.It seems that it broke when I turned it forcibly.

(Did you turn it with a considerably unreasonable force?)

Pull it out with a special tool and you're done.the key isAmazonI was delighted when I told him that I could easily get it.