Madoka Kouenji serves as a gynoid companion to Sayuka Kouenji, living with her and facilitating her transformation into Escalayer. Her core responsibility involves managing the energy needs for Sayuka's transformation, specifically recharging the Doki Doki Dynamo, which demands sexual arousal as its power source. When prior methods, including her own attempts, fall short, Madoka enlists Kyouhei Yanase, capitalizing on his experience to stimulate Sayuka.

Madoka operates with pragmatic, mission-driven efficiency, frequently steering Sayuka and Kyouhei back to their vital objective: defending Earth against the intergalactic empire Dai-Lust. She initially views Kyouhei purely as a tool for enabling transformations, openly criticizing his perceived shortcomings in this function. However, her connection with Kyouhei gradually transcends mere utility, deepening through their shared experiences.

She possesses a self-sacrificing nature, consistently prioritizing mission success over personal concerns. In battle, Madoka engages Dai-Lust forces directly alongside Escalayer, employing a gun integrated into her right arm. Her presence provides a grounding influence for the team, reinforcing their critical duties amidst the chaos of combat and their demanding energy management tasks.