Once upon a time, there was a kingdom, their Prince was very strange, always calling himself a princess. And he always wore princess dresses, even wishing for a prince to come pick him up. He was Grell, the king's favorite son, so no matter how he behaved, the king spoiled him. Grell loves the prince of neighboring country Sebastian, so he always refuses invitations from other princes and kings. But Grell was always rejected and cruelly treated by Sebastian.

One day, the strongest Kingdom suddenly attacked Grell's kingdom. Of course they can't win, but they're hanging by a thread. The King of the Dark Kingdom has arrived to provide reinforcements. Undertaker is ready to help the Kingdom of Grell and help defeat the mighty Kingdom. But he has one condition: Grell must marry him, otherwise there will be no support or help.