Disclaimer: I do not own Naruto or Harry Potter; they belong to Masashi Kishimoto and J K Rowling respectively.

I am making no profit from this story, it is only for entertainment.

Thank you to all who reviewed, favourited and followed this story. I am ever grateful for your support.

So I have a reason for taking this long to update; I have made a plan for this story. Before it was really just taking each chapter as it came, but now I know what is going to happen in the next few chapters and even the ending. So please bear with me.

I have so many ideas and every review I receive goes into the story one way or another. So you guys are writing right alongside me. I doubt it would have been half as good without your contributions. So thank you.

To Elaine Weasley the age line revealed that he was 18 or younger so they currently think that he is around 17 or 18 at the least, rather than the 15 he actually is. They haven't had his age narrowed down.

To Ugh thank you for the compliment about the story being well-written. My story might not be for everyone but thank you for your opinion.

To Lightsbane1905 at the moment until he gets his bearing, he will be eating from the ration pack he has when the others are not looking. This will provide him with what he needs, but he is going to start eating more from Hogwarts.

Also there have been some mentions of the unknown shinobi that may or may not be at Hogwarts. I hope this chapter answers some of your questions, but the real meeting will be next chapter. Also a few questions about fight scenes, they will begin to appear when the other shinobi does.

Thank you and I hope you enjoy Kakashi in Monday's classes.

Chapter 10: Monday

Kakashi looked up from his book to see the boys in the dorm finally awakening. He had made it back the hour before, finishing his night long investigation of the castle.

This place had more secluded and obscure passages than any enemy base Kakashi had seen before. There seemed to be no real thought into how the structure was built, matching his thoughts when he had first set eyes on it.

But underneath the random chaos, there was a defensive structure. The unpredictability of the castle was a weapon in itself.

There had been all sorts of odd features; moving staircases, living paintings, weird little creatures who had cringed at the sight of him. They had worn nothing but the bare minimum to cover themselves and they had been far too submissive.

All things he would need to investigate at a later date. For now he had managed to place seals in the crucial positions; though when he had come across an atrociously pink room he had discovered something that was not so much interesting as alarming.

Seals.

Fuinjutsu, exactly like he could do, what Minato-sensei had taught him. They had been surveillance seals, more used to gather information than to take any kind of action, but they had been there. Which meant there was someone like himself with a mission at Hogwarts; a mission involving the toad woman.

He had left them where they were, not daring to alter them. That would just alert the other shinobi that there was someone like themselves at the academy. He did add a couple of his own chakra-sensing seals, though he made sure that they were placed far enough from the office that they would not be noticed, but with enough range he could get the answers he was looking for.

Until he could locate the other shinobi, all he could do was ensure the safety of Potter.

Once the castle was secured, he returned to the dorm and added extra shielding seals around Potter's bed. Not one of the boys stirred even once at his presence travelling around the room, and once done, had changed into his altered uniform, minus the swishy cloak.

He reset the red scarf around his neck, only taking it off for the time it took to put the black sweater over his head. It rested on his shoulders, a deceptively light weight as if congratulating him for avoiding his nightmares for the night.

At least for the moment; not even shinobi could go forever without sleep.

After a breakfast of jerky and rice from his rations, he had settled himself by the window with the book 1000 Magical Herbs and Fungi, taking the opportunity to use his Sharingan to memorise most of the information after using the necklace to convert it into kanji. He was good with books even without his implanted bloodline, but he did not have the time to learn it all the traditional way.

All the students in his year had had four years of learning, and though he was an exchange student he was expected to have learned it in the school back in Japan. So he needed at least a working knowledge of the subjects in their curriculum so it would not be obvious he had never heard of things such as flubberworm mucus and fairy wings in his life.

He pulled down the strip of cloth as the boys dragged themselves from the too-soft beds. Kakashi had been slightly unsettled when he had sat on his the first time he had gone through his books. His futon back at his apartment was far better; the hard surface of the floor beneath the thin sheets a comforting solid to centre himself with at the end of a particularly draining mission.

Potter and Weasley fumbled through their morning routines, the boy they had been arguing with the day before bolting out the door as soon as he was decent. Kakashi rose from his place at the window, gaining a few glances from the remaining boys in the room. He crossed over to his bed and grabbed a smaller bag to put his books into.

He shrugged on the cloak and followed Potter out the dorm, lifting the strap of the bag over his head. The tan bag was simple, with just one opening for the books, but it was modified so the lining carried a number of supplies. He placed his 'wand' in, and closed it.

Potter turned around just before they reached the common room and seemed as though he was looking for something to say.

"How…how are you doing with all of this? Did you even sleep last night?" he asked, his green eyes looking into Kakashi's grey.

Kakashi raised a single eyebrow at him.

Since the train Potter had been acting differently towards him. When they had first met, Potter had been disgusted by him and his profession but now he was asking after his welfare? Or was he asking for another reason?

"It is nothing I cannot handle" Kakashi replied, reprimand subtle in his tone.

Potter looked at him for a moment, before turning back to the common room and entering, the Weasley boy shooting a look between Kakashi and his friend. The common room was much livelier than the previous night though Kakashi could sense the sluggish feeling that surrounded the students.

Granger joined the boys and they had run into the twins when Kakashi was almost poked in the shoulder. He turned to look at the student who was lowering their hand.

"Good morning, Hatake. It's Hatake, right? How are you?" Longbottom asked, fidgeting.

"Good morning and it is Hatake" Kakashi said.

The chubby looked as though he was searching for some way to continue the conversation, though Kakashi was not sure why.

"What's your school like?" Longbottom asked.

Kakashi looked at him in silence for a moment.

"Sorry if I am annoying you, but you seem nice. You are hundreds of miles from home" Longbottom continued, growing increasingly nervous from Kakashi's gaze.

"It is alright, Longbottom-san. It is natural to be curious. Thank you for your consideration but I must make my way to breakfast" Kakashi said, as he spotted Potter and his friend breaking away from the twins.

He kept his guard up as he passed the twins, their actions at Grimmauld at the forefront of his mind. They were far more devious than they led others to believe. However, Longbottom seemed far too nice. The boy had obviously been victimized in his past yet he reached out to others with such ease.

Their interaction though had confirmed he had succeeded in blending in with the student populace. He appeared to them as strange and an oddity, as he should as someone from a foreign place but enough of a student as to include him into their lives. They were also unsure enough to generally leave him alone.

Now he just had to maintain this for the year.

The first lesson of the day had been History of Magic and the professor looked almost the same as the thing he had seen the day before at dinner. It had all the characteristics that could be used to describe a ghost, but the concept had difficulty sticking in Kakashi's logic-guided mind.

However, during his nightly patrol of the castle and even during breakfast, he had spotted many of these 'ghosts' and they had presented no threat. None of the staff has any concerns and the students regarded them as almost part of the furniture. They also could not touch anything, going straight through everything they touched.

Useless in any combat situation but with potential as a spy.

During the class, he had noted that all the students excluding Granger failed to pay any attention, the majority falling asleep. The worst that Binns seemed capable of was sending his students to sleep, but that was more due to the lack of discipline rather than any special jutsu that he possessed. Kakashi managed to get through the first part of the textbook, extracting what he needed from the never-ending lecture.

Knowledge was the best weapon that any shinobi could possess.

Once this class had finished, he followed the whines and groans of Weasley and Potter down a darker section of the castle, to the Potions classroom.

They entered the dark room and settled themselves on a desk. They appeared to be in pairs though there was enough equipment on each table for each to work by themselves. Kakashi situated himself at the back, only a table behind Potter. Here he could not only see the room clearly, but could reach Potter and the door in a matter of seconds if was something to happen.

A large boy sat himself beside Kakashi, his lip curling in disgust. Kakashi glared back, noting that though there was hostility, there were no indications that the boy would act on it. The fact he was wearing green explained the attitude. He turned back to look at the door.

A shadow swept into the room, his black robes billowing out behind him. Dark eyes scanned the room, framed by long greasy hair. Snape, the missing member of the Order. His eyes found the shinobi and lingered, his lips twisting into a sneer.

He broke into a speech about exams called O.W.L.s, shooting nasty looks at Potter and Longbottom as he did so, and announced the first assignment of the year.

For a member of Dumbledore-sama's organisation, he seemed very hostile towards Potter. It did not seem dangerous; more like vindictive, but it was something to monitor. There was history there and it was not a pleasant one.

"Today we will be mixing a potion that often comes up at Ordinary Wizarding Level: the Draught of Peace, a potion to calm anxiety and soothe agitation." Snape said, pointing out the materials that would be required to create the concoction.

The process reminded Kakashi of making poisons. Although Suna was the real expert in poisons; Konoha was proficient, Tsunade-sama being their best example. Kakashi himself was no stranger to the skill, as sometimes a well-timed drink was more effective than any blade or jutsu.

Best of all, it not require their twigs so all he had to do was follow the recipe. Potions was a subject that required less magic and more precision, as all you had to do was follow the instructions. Though he would need to be wary when they required chakra to make a certain potion; he did not think his was compatible.

However, the real challenge lay in decoding what was required to make the damn thing.

Since he had made his way through the textbooks only that morning, not all of the ingredients were as foreign as they would have been. The instructions made no sense, as how would anything change by stirring it a different way, but Kakashi followed them to the letter.

Other students were not so careful. One of the fat ones had managed to set himself on fire, and Weasley had by far the worst smelling one. The putrid stench invaded Kakashi's senses, blocking out all others until the boy put a cover on his cauldron. The smell remained but it was no longer overpowering.

His sense of smell had been valuable throughout his career as a shinobi, but this was one of the few times he would not mind toning it down.

How could they get it so wrong? He did not even know about any this until this morning, having focused on charms and transfiguration since they would be the most difficult to replicate.

The boy next to him tried to stop his potion from boiling over, the strange purple colour dripping onto the table.

His own result was not what should of happened, but was very different from the other failures around the room. It was the right colour, although it was more a dull grey than silver, but it gave off no vapour. It was just like any other liquid. Judging by the variety of ways it went wrong something was supposed to happen.

Not many had managed to succeed, Potter, Weasley and Longbottom to name a few, and as Snape passed his workstation his face twisted into an ugly expression.

"Settling in, Hatake? Try not to cause any… trouble while you are attending our school" Snape said, his tone condescending as he drew out the words.

Snape spent the rest of the lesson tearing apart Potter's attempt to create the potion, with the green robed students jeering behind him. Kakashi looked at Potter, who stared at his empty cauldron with a mixture of anger and humiliation, and set his own on Snape's desk.

Potter bolted from the room, leaving his friends behind. Kakashi sped to follow, feeling Snape's eyes bore into the back of his head. No projectiles joined them so Kakashi left, catching Potter quickly.

He pulled the boy aside into an empty classroom.

"Potter-san, bare your shoulder" Kakashi asked, taking a brush and ink from his bag.

"Why?" Potter snapped, placing his hand over the shoulder closest to Kakashi as if trying to protect it.

"Do it or I will." Kakashi replied, his lone grey eye glaring at the boy.

Potter stared at him for a moment, still unsure but gradually lowering his collar. Kakashi quickly painted the seal onto the back of his shoulder and pushed chakra into it, the ink lighting up briefly before settling down.

He placed his supplies back into his bag and was about to head towards the door.

"What was that? And before you say something like 'for your protection' what exactly did you write? I know you can't hurt me but I should still know" Potter called out, one hand touching the seal.

Kakashi sighed and turned.

"It is a device that alerts me when poison has entered your system." he replied, watching the boy's eyes widen.

"Why would I need that?"

"I cannot keep testing everything you eat or drink." Kakashi said.

The 'new student' routine would only work for so long, and he could not successful test everything Potter had for the next ten months. He also could not keep eating such rich foods.

His usual diet was enough for a shinobi, but it consisted of lean meats, soup and rice with the occasional ramen and solider pill. Nothing as heavy as they had. He would need to find something more suitable in the massive spread that appeared at each meal.

The pair continued in silence to the Great Hall, just sitting down as Granger and Weasley joined them. As the three tucked into their meal, Kakashi nursed his water, eyes scanning the people surrounding them.

Harry watched the shinobi as the bickering of Hermione and Ron washed over him.

He wasn't eating, just had a glass of water in front of him. He couldn't recall seeing him eat at breakfast either, but he must have. He looked too thin compared to the students around him but Harry was sure that it wasn't because he barely ate.

That morning, when they had headed down to the common room the shinobi was already up and dressed by the time he and Ron had managed to get up. He wondered if the shinobi had actually slept.

If he hadn't then what had he been doing for the whole night? The thought that the shinobi had been moving around their room without waking them, had been watching him sleep unsettled him.

Not only that, but it was strange seeing the shinobi at all. Back in Grimmauld, they had rarely seen him but now he practically never left their side. Watching him interact with others was even stranger. The monotone hadn't changed, and neither had the stone-cold body language, but he had answered when Neville had spoken to him.

He still wasn't totally sure why he had asked the shinobi if he was okay, as since they met the shinobi had been either absent, rude or just silent, but Harry was sure something had changed. It might have been the boggart or when he had spoken to Neville on the train, but the shinobi was not the same inhuman statue they had met the month before.

He had also asked about the sleeping thing, but that was more to put to rest his unease at being watched during the night than for any thoughts of Hatake's well-being.

Of course, Harry had recognized the mistake with Hatake's answer. He could have almost heard the shinobi saying 'shut up and do not question me'. Ron had told him afterwards in a variety of way how idiotic he had been talking to 'him'.

It wasn't as if Hatake could hurt any of them, but it was in moments like that Harry briefly forgot his profession.

He hadn't been able to help the slight fear that had welled in him when Hatake had pulled him into the empty room. It had reminded him of when they first met, a killer draped in shadows. It had been a while since then, but occasionally Harry would catch glimpses of that man.

The man was still a murderer, even if he didn't act like it as much as he usually did.

Harry looked over at Hermione as she stopped arguing with Ron.

"So why the sudden change? You skulk about Grimmauld for a month and now you are chatting with Neville?" she asked, eyes narrowed.

Harry watched as the single grey eye watched her impassively. Chatting was not the word he would have chosen for the stilted exchange between Neville and Hatake that morning.

Though looking into his eye, he could see not reaction to what she had said. The dead, dull feeling in the grey orb did not waver, as it hadn't since they met. Harry glanced at the strip of cloth that covered his other eye and wondered, not for the first time, why it was covered.

Had he lost it or was there something wrong with it?

"I am an exchange student. I am required to build relations between our schools" the shinobi said, his voice in the same monotone it always was.

"But that is not the real reason, is it? Protecting Harry is" she replied, looking for an answer that Harry wasn't sure she would find.

"Potter-san is my guide for the year as I acclimatize to a new environment." Hatake replied.

"So you haven't managed to kill anyone yet?" Ron scoffed, putting his fork on the table.

Though Harry had been conflicted about what to think of the shinobi since the last night at Grimmauld, Ron had never wavered. Distrust and disgust were strong in his expression.

The shinobi merely glanced at the redhead before continuing to look around the room.

"You wizards do not require me to increase the body count" he suddenly said, rising from the table.

Harry froze.

What did he mean by that? Was it a reference to Cedric, to Voldemort? Why would he say something like that?

Ron and Hermione looked equally as shocked as the shinobi rose from his place at the table, looking back at Harry. He tore his gaze away from the silver-haired man and looked around, finally noting the almost empty hall.

"We're going to be late" Harry said, joining the shinobi at walking towards the class. He stood apart from him, still reeling over his words.

Were more going to die?

Kakashi stared at the crazy woman who claimed to be their professor. Since none of the students were showing concern, it had to be true but spouting nonsense about the future? This was a genuine subject?

He and the two boys sat around the circular table, the glass ball in the centre swirling with smoke. They were acting strange around him, more than usual. Weasley still had a grudge against him but Potter had recently been less suspicious, less hostile.

Kakashi figured it was due to the foreign student persona he had crafted for dealing with Hogwarts but he did not expect the boy to be affected by it, knowing as much of the truth as he did. However, now they were both acting hostile, Potter shooting confused glances at him every so often.

Kakashi placed these thoughts to the back of his mind as he listened to the two boys try to make up a dream to interpret.

"I never remember my dreams. You say one" Ron grumbled.

"You must remember one of them" Harry replied, impatience lacing his tone.

The class had been split into pairs but since there was an uneven number, Kakashi just stayed with them. They had been set the task of interpreting dream, and their group was failing at just coming up with a dream.

Weasley was useless, mentioning something about 'quidditch' – which Kakashi was pretty sure was a sport here, having heard it mentioned – and Potter was refusing to say anything of his. Potter suffered from nightmares, and Kakashi could understand wanting to keep them to himself.

The woman strode up to Kakashi, trying a bit too hard to seem whimsical; she had the weird part perfected though.

"You are from a far away land, a land of green and red" Trelawney said, her eyes bugging out behind her large round frames.

Kakashi just continued to look at her.

"It wasn't your fault you know. You have a part in the years to come, do not forsake the future in favour of the past" she said, and floated off to terrorize the next student.

Kakashi stared wide-eyed at her retreating back.

Why would she say that? Does she have access to intelligence that he was not aware of?

The class came to an end and Kakashi left through the trapdoor attaching a surveillance seal to the side of the frame on his way down. As he followed behind Potter to their final class, he adjusted the sleeve on his left arm, making sure the kunai was still secured.

He placed the scroll that matched the seal in his bag, the object resembling one of the their parchments. It recorded what was said and transcribed what the other seal had recorded.

Minato-sensei had come up with it shortly before he became Hokage. It had saved not only time and money from excess missions, but also the lives of spies who could now complete their mission far from the reaches of danger.

Kakashi could still remember Sensei hunched over his desk, mumbling nonsense under his breath as he scribbled away. Kushina-nee had made miso soup that night and had 'insisted' that Kakashi stay for dinner.

It was a long time ago.

They reached the classroom and settled themselves down, the chair in perfectly neat rows and each desk spotless. The pink toad sat at the front, daintily waiting for the last one to straggle in. At least, she was trying for dainty, but with a body such as that, it came across more as though she were bloated.

As the last student darted into the room, she smiled at them and coughed slightly, gathering their attention.

"Good Afternoon" she said, the pitch irritating Kakashi's ears as much as the first time that he had heard it.

He sighed and glared, an uneasy feeling tingling the edge of his thoughts.

This concludes the tenth chapter.

I hope I managed to get the reactions and thoughts of Harry and Kakashi right and that you were not disappointed. Hopefully, Kakashi interacts with Hogwarts as you think he should.

Please could you review about what you like and what I can improve upon.

Also, a massive thank you to Aharah Musici for your review about my Japanese. I have fix the name of the school in the previous chapter and have altered my final sentence.

Arigatou gozaimasu