《地球守护者21》作为前作的续篇，由角川书店、IMAGICA以普通版和限量版OVA的方式发行。全6卷。本作的舞台移到了2001年，是与前作不同的，更写实的故事。世界观也更加黑暗。
由ayanokoji Shoichi领导的洋基队统治着Kisarazu镇。一场尴尬的学校旅行开始了。
A princess's erotic vacation was interrupted by a rebel alien army led by her deadly enemy Aria attacking Happy Planet. When the princess and her plump bodyguard crashed on Earth, she quickly fled and fell into greater difficulties.
