Rônin Akitsu Masanosuke is a skilled swordsman, but his personality often causes him to be let go from his job. One day he encounters Yaichi, the leader of a group calling itself "Five Leaves" and takes a job from him as a bodyguard. Though he is worried about their intentions, he feels there is something more to the group and agrees to work with them.

“韦驮天” × “魔族” × “人类”，世人无从知晓的禁断大逃杀现在开始——
经过一番壮烈的战斗，以压倒性的速度与强大而自豪的战斗诸神“韦驮天”封印了导致世界毁灭的“魔族”，自那以后过了800年。如今，“那场战斗”不过是遥远神话当中的传说故事而已。从出生起一次都没有战斗过的“平稳世代的韦驮天们”享受着安逸的生活，此时不知何人让魔族从漫长的沉睡当中再度复活了——武力、智略、政治、阴谋，总之只要是能用上的东西不论什么都拿出来吧！无规则＆无限制的三方大逃杀现在开始！！