According to its official site, an anime adaptation of light novel Rokujouma no Shinryakusha!? by Takehaya has been announced for broadcast in Summer 2014. More information will be posted on Twitter and announced during Anime Japan 2014 on March 23, 2014.

Synopsis:
When he enters high-school, Koutarou Satomi begins living alone in a 6-tatami apartment for 5000 yen per month. After moving in, he realizes there are cute girls that claim to live in room 106 of "Corona-sou" who call themselves a ghost, a person living in the underworld, a person living in space, a magical girl, etc. The war begins.

ED: petit milady

Cast: Yuuichi Nakamura, Aoi Yuuki, Ayana Taketatsu, Eri Suzuki, Harumasa Oomori, Masumi Tazawa, Maria Naganawa

Twitter: @anime_6joma

Source: Official site


Update March 23
Staff and detailed cast announced.

Staff
Director: Shin Oonuma
Series Supervision: Takehaya
Series Composition: Shougo Yasukawa
Character Design, Chief Animator: Hideki Furukawa
Music: Ryosuke Nakanishi
Producer: Genco
Studio: Silver Link

Cast
Koutarou Satomi: Yuuichi Nakamura
Sanae Higashihongan: Eri Suzuki
Yurika Nijino: Harumasa Oomori
Kurano Kiriha: Masumi Tazawa
Theiamillia Gre Fortorthe: Masumi Tazawa
Karama: Ayana Taketatsu
Komara: Aoi Yuuki
Kenji Matsudaira: Tatsuhisa Suzuki

PV: http://www.youtube.com/watch?v=iAo-qht6wXY

Source: Yaraon, under the section of this scan

Rokujouma no Shinryakusha!? on MAL