You can't, and legally, you can register any way to read certain kanji -- Japanese system only registers how it's written and do not track how to read them. (So

You can't, and legally, you can register any way to read certain kanji -- Japanese system only registers how it's written and do not track how to read them. (Some other government document requires you to register how to read them, but there's no limitation.) So if you really wanted to 淳子 to read completely outside of how it's traditionally read, that's acceptable. So called DQN names in Japan are largely because of this leniency.