Sentou Yousei Shoujo Tasukete! Mave-chan
Genres: Comedy, Sci-Fi
Type: OVA, Episodes: 1
Aired: Feb 24, 2005
Studio: Studio Fantasia
Source: Unknown
Rating: PG-13 - Teens 13 or older
Synopsis:
Rei goes to an anime convention and ends up in a world created by the desires of anime fans. Rei doesn't know how to get back and the world starts to collapse because the convention is coming to a close. 

(Source: AniDB)