Now, Okasaki is the name of a Japanese town.
Family names almost invariably have a topographical foundation, referring to some village, river, street, or mountain, and there may be thousands of Okasakis.

Then, again, it was the custom some years ago for a man to be called one name at birth, another when he came of age, a third when he obtained some official position, and so on.

For instance, you would be called Spring when you were born, Summer when you were twenty-one, Autumn when you became a policeman, and Winter when you reached your present rank." "Oh, Christopher!" cried the detective.

"And if I were made Chief Inspector ?" "Then your title would be 'Top Dog' or something of the sort." Mr.Winter assimilated the foregoing information with a profound thankfulness that we in England do these things differently.
"Why are you so interested in Mr.Okasaki ?" he inquired.
"I will answer your question by another.

Why was he so interested in the Ko-Katana ?" "That is hardly what I told you, Mr.Brett.He professed to be interested in the crime itself.