A phenomenon called the Snow Sea engulfed the surface world, and only a handful of people now reside high above the Snow Sea. When Kaina, one of the members of the last remaining village, goes on a hunt, he finds something entirely unexpected...

The Valghians capture Ririha so they can strongarm the Atlandians into surrendering. The Atlandian soldiers engage in the battle to rescue Ririha and Kaina, but aren't successful. Ririha manages to free Kaina while she remains in captivity.

After learning of the King of Atland's decision to not rescue Ririha and instead go to war with Valghia, it's up to Kaina and Yaona to go save Ririha. Without a means to travel the sea, they must figure out an alternative way to get there.

Once the Valghian admiral receives Atland's message that they will not surrender, he decides to leave Ririha outside to freeze to death. Luckily, Kaina and Yaona come to her rescue, but now they must figure out a way to escape and return to Atland.