Kyō Shiragi

Kyou Shiragi is a mysterious boy who transfers into Yumeji's class and is the overarching antagonist of the series. He is likely replaced by Chizuru in the anime. His real name is Rem.

Appearance
He has a somewhat feminine appearance, especially in his first appearance. He has spikey hair that he keeps held back, with large bushy eyebrows. He also seems to have a scar in the exact same place that both Yumeji and Merry have, only it seems that his is slightly bigger then either Yumeji's or Merry's.

Chapter 107 reveals that the reason why he has the scar on his arm is actually because his arm is really Yumeji's arm.

Personality
He's a perfectionist, and can't stand the fact there are things he is lacking in. However, he also seems to possess a playful atmosphere, when he pretends to flirt with Yumeji to prove he can't get everything. Kyo also seems to be a food enthusiast, which is noticeable during his first appearance. Once his true nature is revealed, his genial facade fades and his true personality is manipulative, calculating, sardonic and even cruel.

History
He had met Merry and Yumeji 10 years before the story, when he possessed Yumeji as a vessel and Merry drove him out. He also knows Isana and may have had control of Yumeji's body when Isana was saved.

A year before the story, he granted some of his power to Pharos Hercules before the latter set out to reality to enact his plan to destroy the Gate.

When the Gate was damaged enough, he crossed over to reality.

It has been revealed that Kyo is actually a new dream demon that only came into existence after Merry left the Dream World thanks to borrowing Yumeji as a vessel. Meaning that until that day, he did not exist and thus has no actual history.

Powers & Abilities
He has the power to make dreams come true (or 'granting wishes' as he puts it) by forcing a dream demon into a person and then killing the dream demon. At first, he could only do this while holding a person's hand but now it seems he can grant wishes simply by willing it into existence. The side effect is that the person making the wish suffers amnesia afterward.

According to Yumeji, he doesn't have a dream aura surrounding him, similar to Merry. The reason for this is that he isn't actually the real Kyo. Merely an extension of the actual dream demon Kyo that still remains in the dream world. He can summon dream demons to reality using drops of his blood. The dream demons emerge from small doors that have structures similar to Merry's key on her keychain.

He sems to know all the dream demons as he calls Engi and John Doe by their names and titles.

John wonders what kind of Daydream Kyo has since, when dream demons cross over, that's the only kind of power they have.

He also possesses quick reflexes, shown when he avoids three of Merry's attacks and when he grabs Anri's hat before it got hit by a truck.

He can also give Dream Demons human forms so they can blend in reality.

He came into existence with all the knowledge he would ever need or require, including things that even Merry and the other dream demons would have no way of knowing about or acquiring information on.

Trivia

 * He has some possible connection with Merry and Yumeji because he has the same scar they both have. Its been confirmed that he knows all about Merry and Yumeji, and knows they have all met before though he is the only one that apparently has memories of those events, unlike Yumeji and Merry. It is later revealed that his arm is actually Yumeji's that was lost and reformed on him, when he tried opening a Dream Demon's door.
 * He seems to be the exact opposite of Merry, in both powers and in relation.
 * Whenever Kyo uses his powers, Yumeji feels pain where his scar is.
 * His real name seems to be based on Rapid eye movement sleep or REM sleep which is associated with dreaming.

Quotes
"I can't stand there being things that i'm lacking in" --ch29

"Hey boss! Give me everything you've got!" --ch27 at the ramen shop

Yumeji: "Hey, man. Are you gonna eat all of those?" Shiragi: "Well, it doesn't sit right with me if i don't get one of each." --ch65 at the donut bar