Doors with actuators are emerging as part of vehicle electrification. It is an innovation that people can easily open and close the door with one button. However, situations where people manually control the door still exist. A mechanical impedance reduction controller is presented as a solution. Various causes of non-linearity such as torque transfer function, friction, and gravity were modeled. Model-based controller is proposed after appropriately compensating for causes of non-linearity. All of the processes considered the actual environment and size of the vehicle door. The effectiveness of the proposed controller was verified with an experiment using a load cell that quantifies the force felt by users.