Skygrazer 

Strange people live in a building called Getenrou. There are boys looking for porn, a space officer, robots, and then...a series of murders!? Officer Sakuraba Saeko's curiosity is piqued by two siblings who appear to hold the key to solving the mystery, and she begins an investigation of her own. Will her “sloppy” logic be able to reveal the astonishing truth hidden in Getenrou? Note: Nominated for the 2012 Manga Taisho Award.