High schooler Yuu and his friend Haru get involved in a case involving his childhood friend Kotona, which forces them to go back and forth between another world that is different but is somewhat similar to their world, Ni no Kuni. The real world and Ni no Kuni, when Kotona’s life is in danger, what’s the ultimate choice the three of them have to make in Ni no Kuni?
In the story, Yuu is a high school student, and his best friend is Haru and his childhood friend is Kotona. Through a certain incident, they travel back and forth between reality and Ni no Kuni. When Kotona’s life is put in danger, the three must make “the ultimate choice.”