In the manga's story, humanity fought against divine beings in a secret war for its existence seven years ago. A girl named Waka, as well as her companions became Valkyries chosen by the gods and gave their lives to end the battle. In time, Waka's younger sister Kiko grows up and enters high school. But now the divine beings have returned.
The Kingdom of Granza is steadily building up its power and expanding its realm. Fleeing from the attack on her home, Faana and her companions hide in the woods, hoping to escape from the Granza Military. However, as her group is hunted down, Faana is the only one fortunate enough to escape alive. Half-dead, she somehow manages to travel several kilometers to the Kingdom of Cordeaa, where she passes out in a lake. Upon awakening three days later, she is surprised to find herself inside the castle of King Yogufu, the ruler of Cordeaa. Faana is even more surprised though, when she meets his daughter, Princess Orfina - the two girls are identical strangers. The two become fast friends, but this period of happiness doesn't last long as Granza soon advances its power into Cordeaa…