Mahou Shoujo Lyrical Nanoha ViVid

Nanoha Takamachi's adopted daughter Vivio has entered her fourth year of elementary school. She receives her own intelligence device, Sacred Heart, which allows her to transform into her adult Sankt Kaiser mode. Vivio befriends Einhart Stratos, who is the descendant of Claus G.S. Ingvalt, a former Sankt Kaiser ruler. They participate in a martial arts tournament where they face various magical opponents, learning more about their past lives in the process.