The Grey Man is a mysterious figure that will appear at seemingly random times throughout the game, and will slowly approach the player.
He wears a grey trench coat and bucket hat of the same color.
He will appear directly where the player is looking at seeingly random times throughout specific areas of the dreamscape. Getting to close to the Grey Man will cause him to disappear in a flash of white, and this will usually reset any "progress" you made in the game, and will take the flashback option away most of the time. The Grey Man is not linkable.
It is assumed that the Grey Man plays the role of the antagonist. However, since the game simply is based on a dream journal, it is speculated that the Grey Man might have personal significance to Hiroko Nishikawa, the person who kept the dream journal on which the game is based.
The Grey Man has been the subject of several stories of fan fiction due to his mysterious nature. However, the Grey Man serves no threat and of course, all of the stories around him are likely to be false. It is unknown why he is in Gameplay at all, perhaps it is simply to give the player a more challenging experience, or he was kept in so that the game remains faithful to the dream journal on which it is based.