The story revolves around an ordinary high school boy named Makoto Niwa and his cousin, a mysterious girl named Erio Tōwa. There is a rumor in their town that aliens watch over it. Erio tells Makoto that Earth has been targeted and says she is an alien herself.

She looks similar to index

AGREE !

another loli type anime ?

Niwa Makoto: Irino Miyu
Touwa Erio: Ōgame Asuka
Mifune Ryūko: Katō Emiri
Maekawa-san: Fuchigami Mai
Touwa Meme: Nonaka Ai

Just dropping in to drop some stuff:

While I haven't been able to find any Denpa Onna to Seishun Otoko's light novel volumes in Kino, there's a related light novel series (sharing the same world setting, even) titled 多摩湖さんと黄鶏くん (Tamako-san to Kashiwa-kun). I've been seeing that title on Kino's shelves lately so make of it what you will for those who are able to get to it. (I can't >_>)

... rikimtasu if you have any info on this please do spoil me hard.

The story revolves around a highschool boy named Niwa Makoto. He lives with his aunt’s family since his parents are away on business. It is there where he meets his mysterious cousin of the same age Touwa Erio — who happens to tie a futon mattress around her upper body and is a self-proclaimed alien. Her staple food is pizza. Erio had been missing for half a year and was found floating in the sea. She doesn't remember anything about what happened during that period of time, but she began to think that it was the act of an alien and wanders the neighbourhood wrapped in the futon.

There isn't a copy of Denpa Onna?
I don't really read Tamako-san to Kashiwa-kun,so i can't spoil at all.
And denpa onna?Wait for anime air and i will spoil very hard.

From 1 - 10 , how good is it?