Ao Oni/Nightmare Fuel

Ao Oni has many versions, each rife with potential nightmares.

• The Oni's face is straight out of the Uncanny Valley, easily becoming a Nightmare Face that the game loves exploiting.
• Hiding in a closet or cabinet can help shake the monster off your trail... but also forces you to sit in complete darkness, listening to its heavy breathing as it stands right outside. If you're lucky, you'll eventually hear it open the door and leave... Sometimes, though, it likes to wait, just to see if it can't fake you out. Getting into a wardrobe while it's in the room? Bad idea.
• The jail cutscenes. Sure, the oni can't get through a locked door... but it can stare you down while shaking the bars. Oh, by the way? Not all jail cells lock. So you might close a barred door and think you're safe, only to have the monster push on through...
• The final cutscene of the first version. Hiroshi, Kazuya and Megumi escape up the well, then go to untie the rope so that the oni can't follow. The oni tries to follow by clawing its way up barehanded.
• The Oni's special ways of Leaning on the Fourth Wall. Mainly, its tendency to hide behind text boxes. In version 6, it manages to invade the inventory screen, too.
• Version 5 includes what appears at first to be a Flash Back explaining how Takeshi ended up hiding in the wardrobe at the start. It's not. And the oni's grinning when it busts the door open, exposing a mouth full of jagged teeth...