In the first book in the Samurai Detective series, Seikei tells the Judge he wasn't afraid when he saw the jikininki because a samurai is willing to face death without fear. The Judge recognizes this as advice from a book by Daidoji Yuzan. That was a very popular book among young samurai at the time. We thought it would be interesting to quote that very passage:

     The samurai, whether great or small, high or low, has to set before all other things the consideration of how to meet his inevitable end. However clever or capable he might have been, if he is upset or wanting in composure and so makes a poor showing when he comes to face it all, his previous good deeds will be like water and all decent people will despise him so that he will be covered with shame.
      For when a samurai goes out to battle and does valiant and splendid exploits and makes a great name, it is only because he made up his mind to die. And if unfortunately he gets the worst of it and he and his head have to part company, when his opponent asks for his name, he must declare it at once loudly and clearly and yield up his head with a smile on his lips and without the slightest sign of fear.

--from The Code of the Samurai, by Daidoji Yuzan, translated by A.L. Sadler (Rutland, VT: Charles E. Tuttle Co, 1988)