Nayuta no Kiseki: KAI tells the story of two heroes, Nayuta and Noah, who have the skills of fighting in close combat with the help of edged weapons, as well as the magic of different elements. The plot begins when rain of stones began to pour on their island and they had to set sail on a ship. Philosophers say that even the ocean has an edge that cannot be crossed, but the characters do not want to believe it. They firmly believe that the world is much larger than what is shown on the map.

While exploring a new area and communicating with new acquaintances, it is worth remembering about your equipment and finding the best armor and weapons. The protagonists act harmoniously, because only teamwork can activate the Gear Craft effect, which is used to destroy the enemy, quickly move around the location, and deactivate defense mechanisms. Nayuta is able to change the seasons, so locations can have snow and blizzards, as well as warm tropical rain or sun.

Each season will feature unique enemies, terrain features, and additional scenes. The developers of Nayuta no Kiseki: KAI have worked hard on every detail, the characters look sophisticated and bright, the area is full of colors and unique decorative elements. It is important to note the soundtrack, the dialogues sound high-quality and lively, and the background soundtrack does not get boring and changes depending on what is happening on the screen.