Royal Carefree Heir

*In the eyes of the people, He was a good-for-nothing Loser.
Originally he would like to have this normal life.
But maybe it is fate’s joke，He was tragical sent to prison after being framed by the Imperial Princess. 
Under such depress he had forced to use the 'Black Tortoise Art' which he inherited from his family to escape.
Under the crisis and power of him, the empire had send him to the border With Princess Rennan who was to monitor his every move.
What is going to happened between them? 
What is he going to do？
To protect this country？
Or be the Lord and take this empire for himself？