Denpa Onna to Seishun Otoko  

電波女と青春男

The narrative centers on Makoto Niwa, a high school student residing with his aunt's family due to his parents being absent for business. It is there where he encounters Erio Touwa, his 18-year-old cousin who claims to be an alien and frequently eats pizza. Despite being missing for six months, she has no recollection of the events that transpired during that time frame. Following her return, she speculates that her disappearance was orchestrated by extraterrestrial beings and roams the neighborhood while enveloped in a futon mattress.