MUNTO

Akuto, the main source of energy is running low and the Heavens, a world of islands, hidden beyond time, floating above ours, has united against the Magical Kingdom whom uses the most energy. To save both the Magical Kingdom and the Heavens and restore the flow of akuto, the Magical King Munto must follow a vision and find the girl Yumemi in the lower world. Yumemi herself is just a normal girl except that she is the only one who can see the islands of the Heavens floating above. When Munto appears before her she starts thinking about hers and others responsibility to the world. (Source: Anime News Network) — Description from AniList community (anilist.co).