In the 6th grade class of the 9th middle school, the class forces Yuri Otani to an undesirable post. She is made part of the Anti-Alien Team. She has to wear a symbiotic alien on her own head in order to fight the aliens that arrive in spaceships from other worlds. While her own alien will protect her, she is scared of it and the enemy. Life isn`t easy in the 6th grade.