The series takes place four years after the events of Magical Girl Lyrical Nanoha StrikerS, during which magical girl Nanoha Takamachi rescued and adopted a young girl named Vivio, who is the reincarnation of the Sankt Kaiser, Olivie Segbrecht. After entering her fourth year of elementary school, Vivio is given her own intelligence device, Sacred Heart, and gains the power to transform using her adult Sankt Kaiser mode. She soon comes across a girl named Einhart Stratos who, similar to Vivio, is the descendant of another Sankt Kaiser ruler, Claus G.S. Ingvalt. As Einhart becomes determined to prove her fighting style is the strongest, Vivio and befriends Einhart and, together with her friends, enters a martial arts tournament where they fight against various magcial opponents and learn more about their past lives.
action android anthropomorphism ass-kicking girls breast fondling calling your attacks cast comedy competition contemporary fantasy defeat means friendship demon ecchi Engrish fantasy fantasy world female protagonist fictional world fighting friendship henshin incomplete story intelligent devices magic magic circles magical girl manga mecha nudity pantsu paper clothes place predominantly female cast present rivalry robot science fiction seinen spellcasting summoning super power swordplay teamwork time tournament training tropes