20世纪末，日本成为世界大国。因此，恐怖组织开始以该国为目标，希望破坏世界政治的稳定。其中最危险的是红色五月，这是一个致力于传播共产主义的组织。为了应对日益严重的暴力，政府成立了一个隐秘组织：特别安全部队.......

In the late twentieth century, the Secret Security Force was formed to stop the actions of the communist terrorist group known as the Red May. Angel, a beautiful, yet cold woman, has recently joined the small anti-terrorist group. But her first mission will be a true test of skill, for members of the Red May are being found dead, murdered by gruesome methods. Who is causing these murders? And why? Written by Chuck "Dark-Side" Williamson

故事描述女主角小樱（木之本樱）与男朋友小狼（李小狼）和其他同学从小学毕业后升上初中的故事。

在一次小樱做梦梦到53张樱之卡上面的图案都消失了，一名神秘人物出现之后库洛牌都碎掉了，

小樱从这个梦醒来翻开封印之书发现库洛牌都变成透明的了!

在与知世、小狼和艾力欧的讨论下，小樱重新踏上了收集透明牌的故事。