故事讲述在五年前，机械王国四灵将之一的华莲，因为发现机械王国的真面目，而从王国中负伤逃出来，被年幼的铁兵所救。而华莲的坐骑B?TX在重挫下已形同一堆废铁，被淹没在机械王国的废铁处理场里。铁兵因救华莲身负重伤，濒临死亡，华莲将自己的血液输给铁兵。事隔五年之后，铁兵的大哥天才科学家刚太郎在某地举行的机械博览会上，被机械王国的爪牙擒往皇国。铁兵为营救其兄而潜入机械王国中，在废铁处理场与王国爪牙铁甲展开一场激战。当受伤的铁兵不小心将血液滴在一堆废铁时，B?TX竟然动了起来。原来只效忠于华莲的B?TX以为华莲回来了，但是在面前的却是铁兵……

Teppei have managed to defeat Machine Empire’s forces time and again, escalating his rescue attempt of his brother into an all out war! His courage has even earned the support of the Empire’s Spiritual Guardians. Together with Teppei, they now seek to learn Machine Empire’s true motives and put an end to their rampant destruction.