evidence: Also, I used to have a friend who had two passports: A Japanese passposrt in his Japanese mother's surname and an American passposrt in his American father's surname. I wonder if it's possible to have different surnames registered depending on the child's nationality, which to me would make sense. [...] It is not a good idea to have passports with two different names these days. It can cause lots of problems when traveling or using passports for identification purposes and the Japanese government realizes this. Even a 100% Japanese person can have problems if traveling in a place like China on a Chinese domestic flight where the romanization of their kanji is mistakenly written with the Chinese version. [...] It is not a good idea to have passports with two different names these days. It can cause lots of problems when traveling or using passports for identification purposes and the Japanese government realizes this.