Want to become a police officer

I am Sri Lankan and I want to know if I get citizenship in Japan can I be a police officer in there? This is my goal. So please answer me.

You need to do some research about visas and citizenship between your country and Japan. Citizenship requires you to have lived and worked in Japan for some time before applying. Visit the website of the Japanese embassy in your home country and do some research first.

If you are more than 20 years old and you need to ask such a question in English on an English speaking board rather than in Japanese on a Japanese board like Yahoo!’mŒb‘Ü then it means you won't a cop in Japan.

Why? Timing! Japanese citizens who want to become cops are young graduates, there is an age limit to sit the police exams. The time needed for you to become a Japanese citizen? Several years after having lived here as a foreign resident with a work visa, speak and write like them? Even more years. Can you imagine filing a police report in kanjis so perfectly that even a native wouldn't notice you are not one?

There is also an other big problem: ethnicity, I saw british cops with turban (I know it's indian...), black cops...but Japan is not like UK, I can hardly imagine a black or a colored/white cop in a Japanese police uniform.

You might need around 10 years or more to achieve this dream. And being a cop in Japan isn't all that exciting. Ask yourself if it's really worth it. It's not impossible, for sure.

Being a police officer in Japan is only possible if you neutralize and being a Japanese.
Also you need to be fluent in Japanese (verbal as well as written)

There is no other way to become a police officer in Japan, even if you married wit a Japanese you are excluded from working in certain public functions.