Nogawa Izumi is a model student and the class representative. However, she faces a growing challenge with an increasingly intense libido that has become disruptive. Her urges have escalated to the point where she feigns illness during lessons to slip away to the nurse's office for relief.
One day, Izumi learns that Earth is threatened by extraterrestrial beings disguised as humans in animal costumes. Surprisingly, her heightened sexual drive might be the key to saving the planet. During her first encounter with these aliens, Izumi is rescued by Usayama, an alien resembling a bunny. His species had previously suffered at the hands of these invaders. In gratitude, Usayama gifts Izumi a special swimsuit designed to enhance her combat abilities against the aliens. However, this suit also significantly intensifies her already heightened arousal levels.
The scientific organization allied with Usayama believes that Izumi’s exceptionally high erotic energy makes her the ideal candidate they've been seeking to confront the alien threat. With the fate of Earth hanging in the balance, will Izumi find the courage and strength to rise to the occasion and protect her world?