Hiroshi entering the annex.
The annex (別館 bekkan) is a dimly lit section of the mansion with red floorboards added in Version 5.2. In Version 5.2, Hiroshi escapes the mansion via the annex. The annex appears much older than the rest of the mansion, with crumbling walls and wooden floors that often have large holes in them.
WARNING: This page may contain spoilers or solutions to puzzles. Read further at your own risk!
The Doll Puzzle
The doll puzzle.
In the recent versions, the main puzzle of this area is the doll puzzle (パズル pazuru, lit. "puzzle") located in the puzzle room (パズル部屋 pazuru heya). There is a sliding puzzle on the wall in which the player can push tiles around a board that assemble a doll (puppet in Version 5.2.) figure.
In both versions, the doll puzzle cannot actually be solved, and only exist so that the player can place a doll head (puppet's head in Version 5.2.) in the hole they obtain from the doll room (人形部屋 ningyō heya), knocking the puzzle aside to reveal a vault.
Version Differences
Version 5.2
The Annex was added in Version 5.2 as a third location after the main house and the basement. It is here that the player encounters the Roach Oni and meets with Takeshi. The player also briefly spots Takuro exiting through a hallway. It is possible to exit the house from the annex via two different paths. The first is through a cracked window, the player can enter the garden and leave via the shed, thereby ending the game. The second being the player finding a cave with a rope ladder in the Annex basement, thus leading to the surface.
Version 6.23
The annex was continued in Version 6.23, although the two exit paths were relocated to the old building. The roach oni was removed, so none of the windows will ever break. In this version, Takeshi would appear to have been hung by either the original oni or Mika Oni in the puzzle room. This is because Takeshi Oni comes out after you, and character onis only are created by an oni killing someone.