战国时期，为了成长为一名杰出的忍者，穷人之家的年轻人乱太郎（加藤清治饰演）进入了一流的忍者学校忍者学校学习。在叶子组学习了一年的乱太郎遇到了好吃又瞌睡的新兵伟（木村丰本饰演）、做过多份兼职的孤儿富丸（林辽伟饰演），以及许多同龄的好朋友。
Joon hyeok is preparing to pass the exam for level nine government staff. Since this is his third attempt, he is sure to pass the exam this time. He moved into a boarding apartment as part of his father's special measures to help his son with his studies. But what awaits Junhui in the luxurious house is not thick textbooks, but two free and unrestrained women. Joon hyeok began his cohabitation with the owner of a boarding apartment full of sexy beauties, Aqiong, and the nurse Dal lae, who exudes sexiness from his face and body. Since then, Junhui has started studying women every night instead of his books.
司馬博士殺される原因となったのは、彼が発掘した銅鐸が、敵の古代帝国である邪魔台国の重要な秘密を握っていたためだ。それが今、司馬宙の体内に埋め込まれている。その銅鐸を奪うために、古代よりの侵略者、女王ヒミカとその配下たちが操るハニワ幻人が襲来する。卯月美和の乗るビッグシューターから射出されるジーグのパーツと、頭部に変形する宙が合体、鋼鉄ジーグとなって磁力を駆使した戦闘用オプションパーツを使いハニワ幻人を倒し、ヒミカの野望を打ち砕く！
