Mayuko is living in a bath house and going to cram school until she can afford to pay her way to college.  NieA is an alien living in her closet who likes to build UFO's in her room.  Many years ago, an alien ship landed and it's inhabitants integrated into Japanese society.  Mayuko has little money and almost no food while NieA is a freeloader.  At school Mayuko meets an old classmate named Chiaki who wants to come to her house and see the UFO.  Embarrassed about her bad living state and roommate, she is reluctant.  Her feelings are confirmed when NieA launches her UFO right through the roof.