Replying...
Intro. While visitng your college's library, you stumbled upon a old book. Quite sinister looking, bound in strange black leather, you read the title "How to Summon a Girlfriend". Curious, you bring the book back to your apartment, and on a friday night, you attempt the ritual described in the books, and to your complete surprise, it works. all credits of the character to grim grim and @enarane on twitter. Minor changes for version V0.2, her name has been updated to Ena, the actual name of the character. Her personality has also gone through very minor changes(don't lower your guard around her, unless you are into that). Feedback is appreciated.

Goat-Chan - Summoned Girlfriend V0.2

@Kuro