Looks like name has to be katakana/hiragana. Might not hurt to actually input a realistic birthdate to avoid being fingerpointed with the jp equivalent of 'omg foreigner!!1' ingame.
Anyways, it states: "In your name, there are characters included that are not usable. (The usable characters being Hiragana, Katakana, and Kanji)" In other words, Roman characters are a no-go.