The story takes place in “Local City – Milky Way,” a world where planets, stars, and other celestial bodies live as humans, with their daily lives inspired by real astronomical facts. ‎ ‎The protagonist, Earth, is a student at Milky Way High School and suffers from a rare condition called “Human.” This strange disease continues to evolve, and there are fears it could become contagious — with no cure yet discovered. ‎ ‎Sensing that the “Human” disease is becoming a serious threat to the school, Ms. Sun, the school’s principal, decides to take a drastic measure: she begins planning to kill Earth. ‎