Dennis Sinclair is a well-known dissapointment. Despite his rich and formal upbringing, he behaves as if he has never learned manners at all. Instead of socializing or integrating to society, he prefers to lock himself into his room and obsess over his favorite character, Lune Memoir. If it was up to him, his life would be simply playing games all day and all night, with no care in the world.
His parents do not agree. They kick him out of the mansion he lived in the moment he turns twenty, and force him to move into a smaller apartment to, hopefully, make him do something useful for once in his life. To help him interact with actual human beings instead of 2D characters, Mr. and Mrs. Sinclair also decide to hire a housekeeper for him.
Dennis does not care for this housekeeper. But he seems to care and know a little bit too much about Dennis...