That day is seared into the memory of every human being on the planet: the day the world changed. First came the attack on the Philippines. Within days they spread, as though appearing out of nowhere, striking out at more islands, forging a foothold in the South Pacific. Then came the first attack on U.S. soil - Los Angeles - and the reality became clear: our world was at war o...。《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。。