Yukinari Sasaki walks home from school, but his neighbor Kirie Kojima beats up Yukinari, inadvertently sending him to Seiren, a planet whose population is 90% female. While there, he meets Miharu Sena Kanaka, as well as her older sister Maharu. Yukinari discovers that touching Miharu does not make him allergic to girls. After being chased around by the locals, Yukinari returns to Earth only to find that Miharu has appeared there as well.