In the modern era, extraterrestrial beings have integrated into human society on Earth. Within the quiet town of Enohana, Mayuko Chigasaki, a financially strained student, unexpectedly shares her home with NieA, an alien belonging to the lower-class 'Under Seven' group. Despite Mayuko's earnest efforts to manage her expenses, NieA displays a carefree attitude towards responsibility. As their contrasting personalities clash, a looming presence of a damaged alien spacecraft adds a mysterious backdrop to their unconventional living arrangement.