Information reaches Rio that her younger sister, Sierra, has been captured by the enemy organization "Death God Empire." Determined to rescue her alone, Rio prepares to infiltrate their base, but is stopped by her superior officer. The officer warns her it's tantamount to suicide, yet moved by Rio's unwavering resolve, reluctantly agrees to accompany her under one condition: she must use the Power Unit. This device greatly amplifies her strength but places extreme physical strain on her body. Rio agrees to return to base immediately if she senses danger, and heads toward Sierra's location. However, upon arrival, she is confronted with the horrifying truth—Sierra has already been subjected to face-sitting torment. Rio realizes this atrocity is linked to Count Gizz, a high-ranking officer of the Death God Empire, who used dark magic to brainwash her sister. Rio fights desperately, but has no means to counter Gizz's sorcery and is gradually overwhelmed by its power. In the end... [BAD END]