Fuyou Yuuna wa Yuusha de Nai

In the 29th year of the Divine Era, over thirty years have passed since an unknown celestial creature devastated Japan, leaving only Shikoku intact. Children now live in safety behind the protective wall, unaware of the past catastrophe. A girl named Yuzuki Yuuna, who shares her name with a fallen warrior from the battle against the monsters, discovers another girl at her school with the same name—Fuyou Lilienthal Yuuna. This girl expresses a desire to leave the wall and see the true world beyond.