Kemurikusa

A story about three sisters struggling to survive in a desolate world surrounded by decaying buildings and red fog. The story revolves around Rin, a girl with an updo. There''s also Ritsu, the big sister who has cat ears and is always calm, and Rina, the innocent, cheerful one dressed in a maid''s costume. Just what is it that these sisters are after in this mysterious world?