In Japan, you can legally be incarcerated for twenty-three (23) days before you are charged, but you do have the right to see a lawyer after the first 48 hours of detention. Note that if you sign a confession, you will be convicted.
I haven't done anything (wrong).
何も(悪いこと)してません。(Nani mo (warui koto) shitemasen.)
It was a misunderstanding.
誤解でした。 (Gokai deshita.)
Where are you taking me?
どこへ連れて行くのですか? (Doko e tsurete yukuno desuka?)
Am I under arrest?
私は逮捕されてるのですか? (Watashi wa taiho sareteruno desuka?)
I am a citizen of ____.
____ の国民です。 (____ no kokumin desu.)
I want to meet with the ____ embassy.
____ 大使館と会わせて下さい。 (____ taishikan to awasete kudasai.)
I want to meet with a lawyer.
弁護士と会わせて下さい。(Bengoshi to awasete kudasai.)
Can it be settled with a fine?
罰金で済みますか? (Bakkin de sumimasuka?)
Note: You can say this to a traffic cop, but bribery is highly unlikely to work in Japan.