Ninja's Battalion "忍者的營" refers to the monumental idea of creation of a clan being diversified into a ninja-based organisation. It is a dispute and cause of series of conflicts between First Division Captain & Second Division Captain during those time. As Second Division Captain came back from a martial-arts exchange program with the asian main-part of the world, First Division Captain was appalled when Second Division members begun to pick-up skills that were not from a traditional clan's background. The First Division Captain was in horror to understand from a news of eavesdropping and reports from the first division that ninja arts introduces a sadistic method into dealing and striking down their foes. If they lose, they'll kill themselves in an act of honor.
"Ninja's Battlion" heightened the levels of tension and conflicts as First Division Captain is getting more insecure and uncomfortable to understand the dark secrets within Second Division, which resulted in the First War Arc.