Boku no Heya no Yuuko-san

Flat broke, a young man is renting an apartment with a "shady history." Nothing's actually happened there—it just feels like something might be looming. You know, ghosts, goblins, curses, no big deal... Until one day, a ghost really did show up and knocked the wind (a very audible fart) out of him. That's how his unexpected cohabitation with the ghost girl, "Yuuko" begins. What started out as bizarre gradually became ordinary—and those ordinary days become irreplaceable. A heartwarming story born in a haunted apartment.

(Source: Square Enix)