Being the Fifth Part of Her Adventures as Master of the ClowBook - 2003
"Who is Eriol Hiiragizawa? Ever since the mysterious boy transferred into Sakura's class, things have been difficult for the former Cardcaptor. Eriol has been testing Sakura with magical trials, but to what purpose? When Eriol and his companions Ruby Moon and Spinnel Sun attack Sakura and her guardians, it seems clear that he's up to no good. If Sakura loses the battle, she could lose Cerberus and Yueh forever!"--Publisher's description.