[2] The first series, "The Nightmare Begins", is a set of 25 stories about a businessman arriving at the hotel after taking a train home from work.

The man soon becomes drawn into a bizarre series of events taking place within Gregory House as he tries desperately to escape from this purgatory.

The second series, "The Second Guest", is similarly set with 25 stories, except this time the main victim is a woman who has just taken a taxi home from her best friend's wedding ceremony.

A manga adaptation called Gregory Horror Show: Another World by Suzuki Sanami started in the November 1, 2007 issue of Weekly Morning magazine; it was then published as a graphic novel and released in Japan, on September 22, 2008.

Thanks to his status he is unable to find an apartment to live in until a seedy real estate agent introduces him to Gregory House.

He is, in reality, Tooru is a 94-year-old man in the year 2078, though part of him could never accept the fact that he grew beyond his twenties without accomplishing anything extraordinary or wonderful with his life.

Though he manages to escape Gregory, like all the protagonists, he eventually wanders back, becoming a permanent guest who refuses to abandon his dreams.

The player must maintain a good level of mental health by sleeping, reading books, or using special "herb" items reminiscent of the Resident Evil game series.

For example, in the 'Bloody Karte' arc, Catherine develops an attraction for Hell's Chef; in the game, the player can find a signed trading card of him in the psychotic nurse's treatment room.

Also, if a player takes the time to follow the guests around the building at various points in the game, they will often divulge interesting tidbits about the hotel and each other.

Gregory Horror Show: Lost Qualia is a Gacha-based RPG mobile game that combines the elements of dungeon crawling with a Gacha card system.

Gregory further explains that the guests delusional beliefs has gotten far too powerful, and that he is able to take over the hotel, turn it into a dungeon, and distort the surreal world around it.

The game has the player, Gregory, or other playable characters going through a labyrinth, where they battle through hostile mages and souls that lurk in the dungeons and can appear from anywhere.