KyuKyu-kun
KyuKyu-kun (named after the sound effects of the rubbing, exact spelling varies) is a character that can be found in the Stairway, which can be reached from Number World. He is often thought to be an example of phallic imagery present in Yume Nikki. Kyukyu-kyun is accessed by stabbing an unhappy-looking zipper tile with the Knife effect. The zipper tile is located in the southeast corner of the Numbers world, to the right of the door with 0's and 1's in front of it. The zipper tile's expression changes randomly. If it's in the normal state, the player is advised to wake up and return until it changes. KyuuKyuu-Kun rubs the pole faster if you use the knife effect and slower with the cat effect equipped. Reaction to Kyukyu-kun is varied; some players find him adorable and others find him unnerving.
"The stare of KyuKyu-kun is that of a monster that doesn't know whats going on, the kind of monster that might hug you, and might hug you too hard, and not know when to stop" -Ok Gold, on Uboachan.
It's as if he is wearing a mask. A fake face. That, or he is too busy and perfectly happy with his pole to notice anything else.
FACE
Although FACE is not a character, it is found in the same place as KyuKyu-kun, so is often associated with it. Some fans use it as evidence that Madotsuki was raped(some rapists get excited from seeing the victim struggle and not exited when the victim "happily" complies, hence why KyuKyu-kun rubs it faster with knife and slower with cat), although this can be interpreted as any kind of penis fear. Alternately, it has also been suggested that FACE could be a sleep paralysis hallucination, which fits with the inability to end the event by pressing any buttons (this suits the "paralysis," a total inability to move) and the fact that Madotsuki awakes once the event ends.
