Otaku no Tonari wa ERUFU Desuka?

In the year 20XX, Japan began exchanging ideas and cultures with other worlds. One day, a beautiful elf moves into the apartment next to Keita Inudo, a high school boy who aspires to be a Mangaka. But she won't be the only girl to push herself into Keita's daily life! Will he be able to cope with all these sudden appearances while keeping his home, his career aspirations, and his sanity intact?