Dr. Marilyn Willow serves as Dr. Narutaki's assistant, supporting his scientific research through laboratory work. She also functions as an announcer during specific competitive events. Marilyn develops an intimate relationship with Dr. Narutaki, becoming his lover. Her physical appearance includes an emphasized bust.

Motivated by jealousy over Marine's involvement in Dr. Narutaki's project, Marilyn designs and deploys the specialized android South Pole One. This android actively interferes with Marine's mission, targeting the same objectives and establishing a direct rivalry. Marilyn utilizes her scientific capabilities to create advanced technology intended to disrupt Dr. Narutaki's primary experiment.

Through South Pole One, Marilyn poses the main obstacle to Marine's progress, creating significant conflict within the storyline. Beyond her professional duties, she exhibits a seductive demeanor and a distinctive physical presence, including a notable swaying gait.