Elementary school students Sumi Washio, Sonoko Nogi, and Gin Minowa are all chosen as heroes to protect the Shinju from the Vertex. Thrust into their first battle against a water-based Vertex, the girls initially struggle to attack it, but soon manage to push it back with teamwork and guts. Following their narrow victory, Sumi works up the courage to ask Sonoko and Gin to be her friends. Half a month later, after the girls beat their second Vertex, they are sent on a training camp to build their teamwork. Later, Sumi and Sonoko follow Gin as she winds up helping a lot of strangers, when the third Vertex suddenly appears. As the girls manage to work together to defeat, Sumi laments that, contrary to her own beliefs, she was the one faltering behind everyone and swears to become stronger.



