The protagonist is a failed university student studying psychology. However, he accidentally discovers a way "to build an absolute hierarchy in the human brain using certain symbols."
He comes up with an idea. He makes a card with the symbols and plays it against his family, who have always mistreated him.
The protagonist begins to take action to subvert Ayaka, the older sister who has looked down on him since childhood, and Reika, the brash younger sister. He dominates the rebellious sisters, and the hypnotic party begins now!