Harry Potter and the demon twins.

Summary: Two transfer students from Japan have come to Hogwarts, they are twins of a powerful demon lord who has been asked by dumbledor to help protect the students from what is to come.

Chapter 1

To begin our story we find Mei and Rei Moon in their home in japan reading books and drinking tea, when Mei looked up and crooked her head to the side and had this curious expression on her face, she shook her head and went back to reading her "About Magical Creatures" book she had just gotten. 10 minutes later a mist started to form around where the two girls were sitting reading their books, the girls looked up when the mist wrapped around them and then a second later they were both gone. The room was silent when their mother came into the room, she smiled and closed her eyes "Good luck my daughters" and then left the room.

(At London, England train station)

A girl could be seen pacing back in forth cursing like there was no tomorrow and a girl shaking her head at that girl.

"I'm really gonna kill him next time I see him nee-san, he does these things all the time it's really getting on my last nerves!" the girl with platinum blond hair said to the girl with short black hair.

"Do try to calm down nee-san, it's not going to help the situation now we're already here and it seems we're going to be going to Hogwarts this year" the girl with black hair said to her angry sister.

"But Rei-Chan I wanted to stay at our schooooool!" whined Mei with a pout.

"Yes well no fixing it now dearest nee-san so stop whining and let's just head to the Hogwarts train before it leaves without us, then Ouoto-sama won't be to happy with us" Rei said to her whining and very upset sister. So without anymore whining from Mei, they both set out to the spot that would take them to Hogwarts Station.

(Hogwarts Station)

Boys and girls were saying farewell to their families for the next 10 months, some were already on the train waving goodbye to their families on the platform. Two girls could be seen watching everything that was happening around them, Mei and Rei got onto the train and were looking for a compartment to sit in. The twins were walking, when they heard some commotion coming from a compartment behind them, so Mei turned around to see what was going on, when she saw a blond male, two big brown haired males, two males one with red hair and the other with brown hair and one female arguing. Mei could see that the blond male was laughing at the male with brown and glasses, she rolled her eyes and watched what was happening between the two males, after a couple minutes the blond male turned around and started to walk towards the two girls, Mei and Rei walked the same way they came walking passed the blond male and his two lackeys. Mei looked at the males out of the corner of her eye and rolled her eyes, the two girls walked to the compartment where they had seen the two males and one female go into. Rei knocked on the door and opened it to see them talking to each other but then stop when the door had open.

"Hi, I was wondering if you had room for two more people in here, it seems that all the other compartments are full" Rei said holding the door open with her palm.

"Sure we have room for two more, I'm Hermione Granger" Hermione said to the two girls.

"Thanks, I'm Rei Moon and this is my twin sister Mei" Rei said sitting next to Hermione and her sister sitting next to her.

"I'm Ron Weasley, nice to meet you" Ron said around eating a chocolate frog. Mei giggled at Ron, Ron blushed when he heard Mei giggle at him he swallowed what he had in his mouth then smiled a little at Mei.

"Your funny Ron" Mei said then smiled at Ron.

"Um..Thanks" Ron embarrassedly said.

"Hi, I'm Harry Potter nice to meet you" Harry said waiting for them to react to his name, but was surprised when they didn't.

"So who was that boy who was arguing with you before?" Mei asked Harry.

"Oh you mean Malfoy, well he always does that any chance he gets, he seems to like to annoy me a lot" Harry said to Mei.

"We might want to get changed into our uniform everyone, so boys out please" Hermione said pushing the boys out of the compartment, shut the door then closed the blinds of the door.

(1 hour later, Arriving at Hogwarts Station)

Harry, Hermione, Ron, Mei and Rei got off the train and walked to where the carriages where waiting to take them to the boats to get to Hogwarts. The twins got into the carriage followed by Harry, Hermione and Ron, they all were able to fit into the carriage without a problem. It took about 10 minutes to get to the lake where they would ride the boats over to Hogwarts castle. All the while the girls talked about everything, Mei telling Hermione about all the magical creatures she had seen in Japan, and Hermione told her about some of the one's she had seen. When the carriage came to a stop a little ways from the lake, everyone got out of the carriage, when they made it to the boats there was only room for four people, they were wondering how they would all get over to the other side together.

"Don't worry about me I'll walk fly over" Mei side putting her hand up in the air and then a broom appeared in her hand. She got onto it and waited for the others to get into the boat. Once the boat started moving Mei's broom followed alongside the boat.

"Wow, thats an awesome broom Mei, where'd you get it?" Hermione asked Mei looking at the gold, silver and diamond broomstick.

"My father gave it to me for my 16th birthday, because I had behaved well that year knowing I was going to get my broom, and the wonderful thing about this broomstick is that if anyone tries to steal it, the broom won't work for them only if I'm on it and I give permission for someone to use will it work for them" Mei said proudly her head held straight and proud. Hermione giggled and Rei shook her head at her sisters posture. When they made it to the other side everyone got off, and Mei hopped off her broomstick and it disappeared when she snapped her fingers.

"Well lets get going before everyone eats all the food!" Ron said running off in the direction of the front doors. Hermione shook her head and sighed.

"He is always hungry never thinking with his head but his stomach" Hermione said walking slowly with the others to the door. Mei laughed and started to chat with Hermione while Harry and Rei followed behind the two.

(Outside the Great Hall)

When they walked into the School Professor McGonagall was waiting with the first years when she saw them walk in.

Mister Potter, Miss Granger your late now hurry, oh and you two must be the transfer students from Japan please wait here with the first years" Professor McGonagall ushered Harry and Hermione into the great hall.

"Now I'm going to bring in the first years and then when we are done with that I'll call you in and then we'll sort you into your rightful house" Professor McGonagall said ushering the first into the great hall. The doors closing behind the first years after they've entered the hall. The twins stood there and blinked slowly.

"Okay then" Mei said shaking her head. Rei smiled and leaned against the wall to wait for their names to be called.

(20 minutes later, in the Great Hall)

"Now it seems we have two new transfer students here from Japan, let's welcome them in, Mei and Rei Moon!" Dumbledore said while the doors open and in walked a girl with platinum blond hair with green bangs that was in a high ponytail, and a girl with short black hair with light green bangs that was slightly spiked in the back. The girls made it to the front of the hall and waited for the professor to call their name to be sorted.

"Rei Moon" Professor McGonagall said holding the sorting hat out for her. Rei sat down on the stool and the hat was placed on her head. A minute later the hat shouted out "Slytherin!" the Slytherin table cheered loudly, Rei waited for the hat to be taken off her head then headed for the slytherin table. Rei sat at the end of the table and put her elbow on the table and rested her chin on the palm of her hand.

"Mei Moon" Professor McGonagall said waiting for her to sit down. Mei sat on the stool and giggle when the hat was placed on her head. A minute later the hat yelled out "Slytherin!" the slytherin table cheered loudly again when they heard they would be getting another person in their house. Mei giggle and walked towards her sister, she sat on the opposite side on Rei and they waited for everything to be done.

(After Supper)

Mei and Rei followed their house mates to their common room, once they got there they went straight to their rooms.

(Next Morning 1st class)

Mei sat next to each other and waited for class to begin, when Mei turn and saw Harry, Hermione and Ron walk in to class, she waved and they waved back at her. Pansy had seen Mei wave at the griffindors and turned to talk to them.

"You know we don't associate ourselves with griffindors right?" Pansy said to Mei, Mei looked at her and raised an eyebrow. The other slytherins watched, Draco watched with disinterest but he become interested with Mei next words.

"Do I look like I care, their my friends so if you don't like it Parkinson don't talk to me" Mei said seriously, looking at pansy with disgust.

"You can't talk to me like that you bitch" Pansy spluttered out angrily.

"I can, and I just did it's not like I'm going to take your advice anyway your not worthy of my time" Mei said turning and ignoring Pansy till class started.

"What you just can't ignore me you little bitch!" Pansy got up from her seat and was about to slap Mei when Professor Snape came in and said "Sit down Miss Parkinson class is started" Pansy sat down with an angry look on her face. Some of the griffindors started to whisper about the new girl and how she just dissed her own house mate.

"Everyone quiet, now get your books out and turn to page 10, you will follow the instructions and I will see who makes it right" Professor Snape said waving his wand and the curtain that hid the stuff to make the potion moved up and tied itself together.

Mei looked at the list of supplies she would need, and she motioned to Rei she would get he supplies and she could set up what was needed to make the potion.

(45 minutes later)

Mei and Rei had finished their potion and waited for the professor to look at it. When Professor Snape came around and saw that they were done he took a sample of their potions and said he would give them their mark next class. Everyone were about finished their potions. Professor Snape had taken a sample of all the the teams potions and said he would give their marks next class. The bell rang and everyone went onto their next class.

(Magical creatures class)

The slytherin and griffindor students gathered outside where Hagrid was waiting for them.

"Today we will be once again be studying Hippogriff's but this time they will be adult Hippogriff's who are know to not be very nice to certain people" Hagrid said gesturing to the adult Hippogriff's behind him. The students watch as a couple of them came forward a bit but stopped a little ways behind Hagrid. A couple of the students thought about going up to the Hippogriff's but thought better of it when they got on their hind legs. Mei crooked her head to the side and pulled out an apple she had with her and took a couple steps forward, one Hippogriff came slowly forward cautiously to where Mei had the apple outstretched to him. The male Hippogriff stopped a couples steps away from Mei and crooked his head to the side and stepped up to Mei and the apple and took a chunked out of the apple, Mei giggled and the Hippogriff stopped and took another step forward and put his nose on Mei nose. Mei smiled and the Hippogriff huffed and Mei giggled when she felt the air on her face, she slowly lifted her hand to pet the Hippogriff then the Hippogriff lowered his head so Mei could pet him.

"Hagrid what's his name?" Mei asked stoking the Hippogriff's head.

"His name is Sir Newton the 2nd" Hagrid replied.

"Well it's nice to meet you Sir Newton the 2nd" Curtsying to the Hippogriff. The Hippogriff bowed back to Mei, Mei giggled.

"You know who I am don't you Sir Newton? Then you also know my sister Rei yes?" Mei the male Hippogriff. Sir Newton nodded his head. Mei smiled and thanked him, then headed back to where her sister was standing.

"Well Class is over know everyone time to get to your next class" Hagrid said.

(In the hallway to their next class)

Rei and Mei walked with some of the other slytherins to their next class, when Rei sensed something in the hallway, but she couldn't pinpoint where it was coming from.

"Rei are you coming?!" Mei yelled from down the hall in the front of their next classroom.

"Coming Mei!" Rei said jogging to where Mei was standing, she looked back and thought she saw a shadow quickly move into the next hallway. Rei shooked her head and enters her next class of the day.

(Slytherin Quidditch Try Outs)

Mei had suggested to Rei that she try out for the Slytherin Quidditch team, and so Rei had said she would try out for this Quidditch team. Mei sat in the stands watching the try outs to see who would make it or not and to see if anyone would try to cheat.

(1 hour later)

Mei thought that Rei did pretty well in the try outs but they wouldn't know till the next day, so knowing that Rei was finished she got onto her broomstick and slowly flow down to where Rei was talking to some of the other Slytherins. Rei looked up and saw Mei flying down on her broomstick, Mei floated next to her sister and sat there quietly watching everyone interact with each other. Rei watched Mei out of the corner of her eye knowing she wanted to talk to the other Slytherins but was not good at saying things to others because of what might come out of her mouth and knowing she might say something not nice.

"Let's go clean up before we head to the Great Hall for diner Mei" Rei said to Mei walking towards the exit of the field followed by Mei.

"Okay" Mei replied to Rei, following her on her broomstick.

(In the hall near the Great Hall)

Mei and Rei were walking towards the Great Hall when Mei saw a pair of shoes hanging from a the ceiling, so Mei took out her wand and did a levitating spell to get them down when they floated down Mei looked to see if she could see who they belonged to, when she found out who they belonged to she did a spell that would wrap them in a box and send them to their owner. So Mei sent the gift on it's way to their rightful owner, and so after the gift was sent the two girls went to the Great Hall to eat.

(Nighttime after hours)

Rei and Mei were already asleep when this black mist seep through the bottom of the door towards the two girls, it started to surround them and then a minute later they disappeared into the night.

(The Forbidden Forest)

In the deep of the Forbidden Forest lay two girls next to each other, one wearing cotton purple shorts and a purple long sleeve shirt, and a girl wearing long cotton pants and a long sleeve black shirt. One of the girls slowly stirred and woke up to her face next to a tree, she shot up so fast that she hit her head on a low branch, she cursed to herself while rubbing her forehead. She looked around and freaked.

"Where the hell are we?!" Mei yelled into the surround forest. Rei shot awake to Mei's yelling.

"What, what wrong?!" Rei replied standing up on her feet and looking around trying to see what Mei was yelling about, all she saw was forest and darkness.

"Where are we Rei-nee-san? I can't see anything" Mei said crawling over to where Rei was standing.

"I think we're in the Firbiddenn Forest near Hogwarts" Rei replied to Mei.

The two girls froze when they heard something move in the forest around them, Rei jerked around and froze her face going white like a ghost. Mei slowly turned around and froze as well when she saw the giant spider then saw the other little spiders around the big one.

"Holy shit Rei what are we going to do?" Mei whispered to Rei.

"Um..I don't know but I'm not moving an inch" Rei replied. When some of the smaller spiders started to come towards them Rei started to freak out even more. The smaller spiders jumped towards the girls and they screamed.

"AHHHHHHHHHHHHHHHHHHHHHHHH!"

End Chapter 1

Characters:

Mei Moon

Age: 17

Height: 5'6

Weight: 125

Hair: Platinum blond with green bangs, always in a high ponytail.

Eyes: Blueish-green.

Species: Half-demon,Half-witch.

Clothes: Hogwarts girls uniform.

Jewelry: Three studded earrings in each ear, a diamond snake necklace, three diamond rings on each hand, and two diamond bracelets on right wrist.

Chosen animals: White Ferret named Shin, and an black/white owl named Lika.

Likes: Animals, gummy bears,singing and chocolate.

Dislikes: Know it alls, popular girls who think their all that, and cheaters.

Rei Moon

Age: 17
Height: 5'8

Weight: 120

Hair: Short black with light green tips, thats somewhat spiky at the back.

Eyes: Blue outlined in green.

Species: Half-demon, Half-witch.

Clothes: Hogwarts girls uniform.

Jewelry: Two studded earrings in each ear, a diamond skull necklace, two diamond rings on each hand, and three diamond bracelets on left wrist.

Chosen animals: White owl with black dots named Dexter and a black cat named Haku.

Likes: Sweets, reading, flying on her broomstick, and casting spells on people.

Dislikes: Slow witted people, spiders, teachers, and being in class.