The space guardian warrior Firewoman fights daily against the invading Slave aliens threatening Earth. During battle, Seina Aoi gets caught in the Slave aliens' conspiracy and suffers a fatal injury. Yet she chooses to transform into Firewoman to defeat the electric chair kaiju Sittinga, overcoming immense pain to destroy her enemy. After the battle, Seina collapses, reverts to her original form, and is captured by the Slave aliens, subjected to brutal torture. However, with the help of her comrade Endo risking his life, she escapes. Filled with rage and sorrow, she transforms once more and heads toward Planet Yuda to pursue the Slave aliens—only to find herself trapped in a deadly ambush... [BAD END]