denpa onna to seishun otoko
Denpa Onna to Seishun Otoko (電波女と青春男, transl. Ground Control to Psychoelectric Girl) is a 2009-2011 light novel series written by Iruma Hitoma and illustrated by Buriki, with a manga adaptation illustrated by Yamane Masato and serialized in ASCII Media Works' Dengeki G's Magazine, and 2011 anime adaptation by SHAFT.
Due to his parents' overseas work, Niwa Makoto moves to the city to live with his 39-year-old aunt Touwa Meme. The boy, who expected to live a dream life with a harem, is instead confronted with a hitherto unknown relative: Meme's daughter Erio, a strange recluse with a fascination for aliens. Makoto has since been trying to help her open up, even as he gets to know more about his cousin.