Ayu ..
wouldn't be in Wal-Mart.. sorry. She's not signed onto any International/American record label
Nami Tamaki is with Tofu Records, the company that is
attempting to make Japanese music popular in America. She's a good singer, her stuff is a lotta trancey/dance/pop music.. it's very good, I recommend it
Puffy Ami Yumi just came to America for a tour in California and New York.. otherwise, I'm not really into their music