Lin Que inherits a dilapidated Happiness Apartment and binds with the Black-Hearted Landlord System. He invents pretexts and clear price tags to increase revenue, charging for everything from rent to various shared facilities. While the tenants complain that he is black-hearted, they nonetheless tangibly enjoy upgraded hardware and development opportunities. Subsequently, food delivery workers, construction foremen, dream-chasing web novel authors, musicians, and large groups of elderly people appear in succession, and Lin Que opens a senior health experience center using street-facing commercial properties. The system possesses a mirror-revenue capability, where income generated by tenants' creations produces extra earnings belonging to Lin Que, without damaging the tenants' income. With dark humor, the entire drama portrays the hilarious stories between the landlord and all kinds of colorful tenants.