Tsukasa Tenma is the eldest son of the Tenma Family, training to finally become a king. However, clashes from other kingdoms rush the day of his coronation sooner than expected... With both of his siblings relying on him, and the disappearance of the eldest child, Kanade Yoisaki, sudden raids from mysterious forces, it all depends on Tsukasa to save it all. To save his kingdom and prove his worth for good.