There isn't a Japanese girl's name which sounds "Marta", so how about are similar names as "丸子 （maruko), 麻亜子(maako)?

Thanks to all of you for the answers! Yah, exactly, I just got Dragonball raw manga :) Its fun to read, cant find many words in the dictionary tho :[ So now I´ve got the translated and the raw and try to figure out what some words mean by comparing :D

if it is family name,"marta" write "丸田"　or ”丸太”. well,i saw your glupe post. could you get row manga? Probably, Amazone japan can send manga to foreign countrys. I read dragon ball.it's fun (^-^) i have all title! i hope you can get manga & enjoy it(^^)v

"Marta" is not Japanese name. So you can not use Kanji. You had better write "マルタ" in Katakana. If you're forced to write in Kanji, we can not deliver your letter... In Japan if you write her name in other language, we deliver your letter.

Marta is not a Japanese name, so it has no Kanji. You'll have to use katagana マルタ.