Erin, a mercenary traveling with the sword spirit Nighthawk, encounters Nighthawk's sibling, Tomcat, who requests help gathering materials to complete a magical device. To fulfill this quest and earn a living, Erin navigates a series of provocative challenges, from battling goblins and enduring a shrine guardian's trial to working a temporary job as a bunny girl.
Erin and Nighthawk continue their journey, encountering slimes and a shrine guardian who subjects Erin to a series of erotic "transformation trials," turning her into a busty cow-girl and a cat-girl to earn rewards. After a series of suggestive mishaps with a photographer and a cheerleader role, Erin faces a mysterious mirror version of herself, hinting at a hidden past.
Erin and Nighthawk travel through the desert and mountains, where Erin takes on the roles of a nurse and a nun to provide "therapy" and "salvation" to those in need. Along the way, she must endure a series of provocative trials at various shrines to obtain rare materials and rewards.
After indulging in a lavish maid orgy and completing a trial of obedience in underground ruins, Erin receives a powerful but provocative set of bikini armor from Tomcat. The armor attracts a monstrous mummy, leading to a series of erotic encounters and a final confrontation with Tomcat himself. In the aftermath, Nighthawk reveals that while Erin's body is fully healed, she chooses to remain by her side, cementing their deep spiritual and physical bond.