Becoming a Japanese Citizen?

Question:

I was just reading about culture shock of Japan. I read that some people end up loving Japan so much, they become citizens of Japan.
What really caught my attention was:
"Not only do you have to adopt a Japanese name, but you have to renounce your citizenship from your native country."

What I'm mainly concerned about is, is it true you'd have to give up your citizenship from your native country?
And second, what does it mean by adopting a Japanese name? First name? Last name? Both? Even without marriage?

Answer:

It is extremely rare and difficult for a single person (without getting married with a Japanese) to get a Japanese citizenship.
1. Yes, you must renounce your native citizenship.
2. You don't need to change your name, but you should register your name in Japanese (katakana is OK).
Hmmm, yes, you will lose your name legally.
If your name is Angelina Jolie, you should legally register it as ジョリー・ アンジェリーナ, and you are not Angelina Jolie any more.
Isn't that awfully scaring? If I was not a Japanese, I wouldn't do that.