Yuuki Yuuna wa Yuusha de Aru: Washio Sumi no Shou 3 - Yakusoku

After the loss of Gin Minowa, Sumi Washio and Sonoko Nogi are left to continue the duty that once belonged to three friends. The attacks of the Vertex grow more severe, and the Hero System is upgraded to grant the girls far greater power. That strength, however, comes with a price no sixth-grade child should ever have to pay.

Even as fear and grief close in, Sumi and Sonoko cling to ordinary school days and to the promise connecting them to Gin. Their next battles reveal the cruel truth behind the power entrusted to heroes, pushing both girls toward a fate that will reshape their bodies, memories, and the lives awaiting them afterward.