I didn't know it was her who appeared in the "For My Dear..." PV. Thanks, you learn stuff every day!
But I'm really sad for Ayu now, she mentions her A LOT in that All night Nippon broadcast indeed, and they seemed extremely close
EDIT: Random (as the MF link available at AHS died some time ago), but if somebody wants that All night Nippon in audio format then get it here:
http://www.sendspace.com/file/9u7gb0