MMM, I think immigrants to the US adopt English names all the time. My high school friends' birth names were things like Chun-yu, Yan-ting, etc. Yet they all went by names like Adam, Lisa, etc. even though their legal name wasn't that. Note that you've moved from criticizing the use of kanji in a non-Japanese writing his name to criticizing a non-Japanese person adopting a name more popular in his new home country. My example here seems to argue well against your second point, and my Arudo Debito point seems to argue well against your first point.

We're still left only with that it's possible in every way, but choosing a long transliteration can be very harmful to the wrist.

And honestly, if a Japanese person is upset that you're using the same last name that he has, he can go suck an egg. You're required to take a Japanese name when you naturalize. Is it illegal to adopt a Japanese name that already exists? No: because I don't think having the same name as someone who isn't related to you isn't so great a problem as you make it out to be.

Of course, if you take the name Koike and then claim to be related to Kazuo Koike, that's a problem, but not a problem of last name, but a problem of going beyond that and affirmatively claiming relation. I don't think when Japanese people meet a Hamasaki they assume the person is related to Ayumi Hamasaki.

Here's another example.

A famous Anglo-Canadian comedian living in China Mark Henry Rowswell already has a Hanzi (Kanji in Mandarin) name. He is called 大山 (dàshān) in Chinese. His Hanzi name is not even based on his English name.

Shou-Koku-Fu is how I would read that in Onyomi (though I am not a native).

Points well taken, Kyle. I may have stretched my argument too far. I would maintain that he isn't going to find kanji that universally read "jacob" or anything near it...especially with the generally used name kanji. And if he chooses kanji that aren't generally name kanji or are decidedly NOT name kanji it won't even appear as a name to the general Japanese eye, but look like Chinese and/or gibberish. And what's the point of that?

I agree with you there, MMM. I would counsel against creating a Japanese name for oneself, especially without help from a native. Better to just go with the katakana transliteration (or, in some cases, adopt a "real" Japanese name in the case of naturalization or if Japanese people have trouble with your transliterated name for some reason).

That is good idea.
I checked translation way of Jacob in Chinese,
Jacob - 雅各,雅各布
is used for even American people instead of difference of pronunciation.
(ya-ge-bu)

MMM, this is Chinese. not Japanese on-yomi.　
捷克布 in English, 捷克布 translation by Nciku Dictionary

I was wondering, what would Derick be in kanji? My friend wants to get a tattoo of his name, but katakana doesn't really look as nice. Chinese is fine if anybody knows... Also, I guess the name Derick means "power of the tribe" if there is any corresponding kanji meanings there.

Did you even read any of this thread?

Never mind. Have him go with 出陸 so people will point and say Why does he have "jutting landmass" tattooed on his arm?

lol, jutting landmass, thats just awesome. My friend has kanji on both her arms and i always joke they mean Dumb American lolz

I did read it actually. I realize in japanese katakana is best etc. However, foreigners have to have their names in Chinese kanji right? Because there is no katakana in chinese. I realize katakana is the best way, etc. but it does not look as good, as i said above.