Aoki Umi no Toraware Hime

Overview

In the only neutral country surrounded by many other countries, Kourozen, also known as God's country the princess, Matsurika, is troubled by a proposal from Prince Orland of Cantabria, a major power. One night, Matsurika is suddenly kidnapped by an intruder and brought to the open sea. The man, Raju, who calls himself a pirate, says he will sacrifice Matsurika on the legendary altar, to attain his wish--- The princess of God's country, the pirate surrounded by mystery. A pirate tale about an ancient lore and the legendary altar. Let the battle begin!!! (Source: Forbidden Garden)

Source: AniList