Hi no Hime to Mizu no Ou

Overview

One night, Ilia, a shrine maiden who serves the god of fire, hides Ateiga, a boy who is protected by the goddess of water, from his pursuers and saves his life. Four years later, what will become of Ilia, who has been caught up in a war and sentenced to be buried alive? (Source: Tosuisha, translated)

Source: AniList