Valkyrie no Kiko
ワルキューレのキコ
Seven years prior, a hidden conflict between humanity and divine entities nearly destroyed the world. A girl named Waka and her allies were selected as Valkyries by the gods and sacrificed themselves to bring the war to a close. Now, Waka's younger sister, Kiko, has grown up and begun attending high school. However, the divine beings have reappeared, signaling a new threat.
