NEED NOT TO KNOW means "don't need to know" in Chinese and "know what is necessary" in Japanese translation. This is a sentence said by police officer Bai Niao in Conan's theatrical version of The Assassin in the Pupils, which is a police code word. They often use this sentence to avoid the topic and hide the secrets of the police. This is not the special language of our police.

Shiratori Ninzaburō is Bai Niao's father. The metropolitan police department searched for a class of compulsive criminals and the third police department. Later, he was promoted to the police station and became a colleague of Megure Jūzō Police Department. He has a certain reasoning ability, and thinks Conan's reasoning is just a child's play and coincidence (obvious in the early stage).

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In fact, Bai Niao, like Moritani II, is the original character in Conan's first theatrical version of Exploding Skyscrapers. Later, the author G?sh? Aoyama joined the original comic book and became the first drama character to enter the original comic book. Later, he gradually became the protagonist in comics. Except that M 17 Detective of the Sea and M 19 Sunflower of Fire only appear in the preface, and M2 1 Love Song of Tang Hong does not appear, Bai Niao is very active in other theatrical editions.

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Baidu encyclopedia -—NNTK