X Maiden
Japanese title: エクスメイデン
Type: ONA
Episodes: 8
Source: Game
Genres: Comedy, Slice of Life
Producers: Lambert
Duration: 11 min per ep
Rating: PG-13 - Teens 13 or older

In 20XX C.E., a mysterious alien race named Firow suddenly appears on Earth. The Firow's dreadful attacks force humanity to engage in a difficult battle. But humanity's last hope, the X Maiden who wear weapons built to destroy the Firow, are about to set out.

(Source: ANN)