In a town plagued by the Hamerudah, an evil army that abducts young women, shy student Himesato Rin is saved by the Magical Battle Maiden Frostia. After meeting the spirit Mii and witnessing Frostia in danger, Rin wishes for the power to fight and transforms into the Magical Battle Maiden Lyristia. Despite a harrowing encounter with the enemy, Lyristia unleashes her magic to secure victory and vows to stand alongside Frostia to protect the city.
Rin learns from the spirit Mii that the Hamerudah are energy-stealing monsters who target women to fuel their conquest. Determined to rescue the captured Hiyama-senpai, Rin transforms into the magical battle maiden Lyristia and confronts the enemy in the city. However, she is quickly overwhelmed by a swarm of grunts who attempt to drain her energy through sexual assault. Although she manages to convert their mana into a powerful counterattack and locate the enemy base, Lyristia is left physically exhausted and desperate to find a way to save her friend.
Lilustear teams up with Kishibe to stop Hamelder, a sinister group that kidnaps women and uses addictive substances to break their will. After Kishibe acts as a decoy to lead Lilustear to their secret base in a closed shopping mall, Lilustear must fight through an onslaught of pleasure-inducing attacks to save her friend. While she successfully defeats the Hamelder members, she learns that the other captives, including Hiyama-senpai, are being held by another mysterious group called Sebushya.
Lilustear confronts Hamerudah's forces and is lured into a treacherous underground fortress. Despite being captured and subjected to a brutal assault by a sadistic enemy, she manages to fight back and extract the location of Hamerudah's central base. As she recovers from the ordeal, a ruthless hunter named Kuhizan appears, intending to prey upon the magical fighters for their energy.