When the infamy of the Demon King echoes to the ocean's depths, Yuria, the king of the sea, decides to venture onto land and challenge them. However, the very act of gaining two legs robs her of all her power, transforming her into a helpless child. Now faced with this unexpected twist of fate, can Yuria rise above this setback and defeat the Demon King to claim her place as the most powerful being in the world?