Shougo Mikadono

As the chosen successor of the Mikadono Group, Shougo carries the weight of his late father's final wish: transfer to Shinryuuin Academy and secure a marriage partner before graduation in order to rightfully inherit the family empire. His new school life takes an unexpected turn when a mysterious girl calls him claiming to be his long-lost sister—one who has secretly enrolled under a disguise with the sole intention of marrying him. Caught between a growing circle of admirers and a hidden identity he must uncover, Shougo races to expose the truth before unknowingly crossing an irreversible moral boundary.