Unicode/Japanese characters not displaying

I've never had this problem before. I synched up my iPod this morning, I added a new album with Japanese kanji and then disconnected. After leaving my home for the day, I looked at the album I just imported and all of the kanji isn't showing up, nor is the UNICODE characters. All of the katakana and hiragana still show up, but the kanji and UNICODE are just blank. This has never happened before and my iPod is set up for English and I've never had this problem. Any ideas?