Do you change your name to go to live in Japan?

Question:

If you go to Japan, do Japanese call you by your western name, can they pronounce it ? or do you take a japanese nickname, and if so is there a specific way to choose one ?

Answer:

No name changes, your name just gets 'translated' with katakana. This means that your name rarely ends up sounding like it used to. This is especially true if you name ends in a consonant as all Japanese words end in vowels. Mark would end up as Ma-ku for example.

As for kanji, I've seen some weird types that find kanji to spell out/sound out their names. Such is not official though.