Sou Kagura is enjoying his life as a new high school student until one day when his parents abandon him due to a large debt they had amassed. To get rid of their debt, they essentially sell him to Mikoto Ouzuki, a wealthy land developer who wants Sou as his sexual pet. However, Sou's older sister Ui intervenes with a proposal: If Sou can pay back the debt in one year, he's off the hook, to which Ouzuki agrees. Sou's life is turned upside down as he navigates his new circumstances.