From MangaHelpers:

Uchida Kaede is a young woman who has left her remote countryside village and migrated into Tokyo to find a job and make a living. The huge, crowded, urban environment is alien to her and she finds it terrifying. During a search for suitable accommodation Kaede meets and befriends a kind, seemingly normal, local estate agent. Little does she know that this man hides a dark and sinister secret. This fateful encounter sets off a sequence of stalking events, which gives Kaede something to be really terrified about. [Kikuna992]