Unlike that of many countries, the Japanese government has the legal authority to prevent parents from giving their children certain names -- say the kanji incarnation of "Spiderman."
In order for the birth of a baby to be registered with local authorities in Japan, all the kanji in the child's given name must be chosen from characters approved by the Justice Ministry. Parents are allowed to select from the 1,945 general-use (joyo) kanji and a list of name (jinmei) kanji, or, alternatively, to write the name in kana.
Last June, the ministry announced that the 285 jinmei-kanji list would be expanded, and, citing increasing diversification of values in Japanese society, that the public would be allowed to have its say in the matter.