Disclaimer: I do not own Naruto, nor do I own the concept of Fuinjutsu (these are owned by Masashi Kishimoto).

Additional Disclaimer: All of the ideas and branches of Fuinjutsu listed here along with their specific techniques, at least as I explain them, are of my own creation. Any resemblance to another author of Naruto Fanfiction is unintentional and purely coincidental. I despise theft, and I also have no respect or tolerance for those who steal the hard work of others and pass it off as their own. If I have unknowingly "taken" another author's hard work, or if my own work resembles another author's work too closely to be considered original, please feel free to PM me and let me know, and I will be happy to either make enough alterations to make it my own, or give said author credit for the creation.

IMPORTANT: The pairing of Naruto/Kurotsuchi is not the main focus of the story; the creation of the Discipline of Fuinjutsu is. This story, and the book that Naruto is creating in it, is not a comprehensive list of Fuinjutsu (though I would certainly like to get as close as possible to this). It is meant to add on to already-existing methods of Fuinjutsu, and will likely always be a work in progress. In addition, if anyone has any additional ideas for adding either branches of fuinjutsu that are not presented here, or specific types of seals and arrays that are not presented here, feel free to PM me, and if I can do something with it, I will create a suitable explanation. I will also give you credit for the idea.

RIGHTS OF USE: Any author who wishes to use any of the techniques listed here can assume ncpfan's permission to do so, as long as you give ncpfan credit for the idea (please see additional disclaimer above).

As a couple, most people found Naruto and Kurotsuchi Namikaze to be rather odd. It was clear that they were one of those couples that was "meant to be", as they enjoyed being with each other more than most couples did, and they interacted with each other in a way that was so far off the beaten path, yet it worked so perfectly for them. They had developed so many passions and hobbies that they engaged in and enjoyed together, that it only served to make their bond stronger as time went on.

At first glance, one would think that they were more inclined to athletic and physical activity than anything else. Both kept in peak physical condition, as the rigors of their shinobi careers demanded, and their bodies showed their devotion to physical training. On top of this, they both enjoyed very outdoorsy pastimes, such as hiking out in the woodlands surrounding Konoha, or going on week-long camping trips inside the Forest of Death, always bringing hunting and fishing gear in, and a lot of excess meat back out. When they came back into the village from these little excursions, both of them usually looked bruised and beaten up, wearing blood-stained shredded clothes and mile-wide grins. Yeah, they were a bit odd…and creepy.

However, they were also very charismatic, both individually and as a couple. They would become the center of attention anywhere they were seen or the life of any party they went to, simply by way of them being who they were. They both enjoyed talking to people, and their own "schmoozing" skills had only increased as they continued performing their diplomatic and consular duties.

What made them particularly odd in the eyes of most people, however, was their love and enthusiasm for the art of fuinjutsu. While the Namikazes were really cool to be around most of the time, whenever the topic of fuinjutsu was brought up, both of them turned into the biggest nerds that anyone had ever met. What made them even more odd, and a tad bit scary to many, was that they could explain fuinjutsu so well, and make it so seemingly easy to understand for anyone else, that almost anyone who listened would become a fuinjutsu nerd themselves, at least when in Naruto's or Kurotsuchi's presence. Yes – they were rather odd, indeed.

At the moment, Tsunade and Kurotsuchi were watching as Naruto was engaged in a moment of "oddity", as he was talking about his favorite ninja art with several different foreign dignitaries in one of Tsunade's conference rooms. Kurotsuchi was watching her husband with stars in her eyes and a faraway smile on her face. Tsunade was watching with a rather different expression: confused and morbid fascination, with more than a hint of jealousy.

"How does the brat do it?" Tsunade asked, the hint of bitterness in her tone of voice reflective of the jealousy she was feeling.

"Hmm?" asked Kurotsuchi, having her attention drawn away from Naruto by the sound of Tsunade's voice.

Tsunade pointed to Naruto and reiterated her question, with some frustration added in, "How does Naruto do that? There he is, in nerd mode, keeping people who have no background in the ninja arts at all completely fixated on him, talking about seals of all things! If I tried talking to them about medical ninjutsu like that, I'd be hard-pressed not to put them all to sleep!"

Kurotsuchi smirked playfully and began to tease the busty Hokage, "Why Grandma, that's not the cold, hard edge of jealousy I hear in your voice, is it?"

Tsunade didn't miss the way the words "cold, hard edge" were drawn out a little more than the others were. With a tick mark on her forehead at Kurotsuchi's adoption of Naruto's nickname for her, she replied in a resigned, yet still frustrated manner, "Yeah, maybe…"

Kurotsuchi gave her a patronizing grin as she put her arm around the older blonde's shoulder, "Oh come on, Grandma Tsunade, don't be like that! Some of us have got it, and some don't! I mean, look at me! I love fuinjutsu as much as he does, but I can't project my enthusiasm for it the way he can unless he's actually there with me."

This seemed to help Tsunade to lighten up a little, as she gave a small smile, "Yeah, I guess you're right."

Tsunade just watched and listened to Naruto as he was explaining his art to those assembled in her conference room. She couldn't help but feel a swell of pride as she observed them hanging on his every word, and before long, she was caught up in the lecture herself. Naruto knew quite a bit about seals that Tsuande was not, and she was rather surprised at what she learned as she listened to him talk.

Kurotsuchi simply glanced back and forth between Naruto and those who were currently his audience, her face adopting a satisfied smirk at their reactions. They were all fixated on him, Tsunade included, to the point where they weren't even aware of anything else going on around them. Kurotsuchi eventually decided to just sit back and admire her husband's ability to understand and teach their favorite ninja discipline, listening intently, as if for the first time, as Naruto simply talked about the core basics of the art as he understood and defined them within the first chapter of their co-authored book…

CHAPTER 1: FUINJUTSU – THE CORE BASICS

A Brief History of Fuinjutsu

Fuinjutsu has existed for untold millennia. This art existed long before the arts of ninjutsu and genjutsu, and even before the concept of chakra was introduced to our world. This art has existed in many different forms, and under many different names, some of them even "arcane" in nature. Arts such as "rune magic" or "warding magic" were in fact precursors to what we now know as fuinjutsu!

While not much is known about the two precursory arts, the two main known differences between the arts as they were and fuinjutsu as it is now was the manner in which the seals (or runes/wards) were activated, and the ways in which they were used. With what we know of the three arts, it is fuinjutsu that is the most versatile and has the widest range of uses.

Ironically enough, since its inception, and especially since the time in which the ninja villages were founded, the art of fuinjutsu has been a very ambiguous art passed down largely by individual instruction and word of mouth. It has been obscured to such a successful degree that one of two viewpoints has developed: either it has been looked down upon as the least useful or least threatening of the ninja arts, or it has been feared to a degree that those who practiced it were persecuted, to the point of wiping out entire nations, such as Uzushiogakure, and Uzu no Kuni. It is to be noted that there were several important reasons behind this practice of obscurity.

The main reason was that only one nation, the aforementioned Uzu no Kuni, practiced the art as a staple in the training and education of its shinobi. Many of the seals practiced there were considered national military secrets, and as such, they were closely and jealously guarded in the same manner that any other hidden village would guard its own native jutsu library. As such, the other nations, and even the greater hidden villages, oftentimes stood in awe and in fear of this practice that flourished in a much smaller hidden village.

The second reason for the obscurity was that there were seemingly so few people who had the ability to understand this art on even a fundamental level. The techniques and terms that were used, as well as the manner of thinking required to develop even a base-level proficiency in the art of sealing, made this art appear to be completely beyond the grasp of the average shinobi, and even many shinobi that most would consider exceptional. As such, instruction in this art was so limited and rare that groups of students were never taught: it was always a master who taught an apprentice (or in rare cases, two apprentices).

The third reason behind its ambiguity was that much of the time, fuinjutsu was simply taught technique by technique, and seal by seal. Many that were even considered seal masters sometimes only had a few seals in their arsenal, all seemingly unrelated, but what made them "masters" was their ability to use the few seals they had in a variety of ways, making it appear that they actually knew more than they did. This is also a testament to the versatility of this amazing art: that so many things could be done with so few raw components to work with.

Notable fuinjutsu users in recent days have been few and far between. Only a handful of people could ever claim to have developed the degree of proficiency in this art to be labeled seal "masters". Though there have been many who could claim a much higher degree of proficiency in fuinjutsu than most, in the last 100 years or so, only six people could claim the title of seal "master" when alive. In order of their reported levels of ability, from greatest to least, they were: Kineda Uzumaki (Father of Mito Uzumaki, and Uzushio's God of Seals – rumored to have the same level of ability with fuinjutsu that Hiruzen Sarutobi, the Third Hokage of Konoha, and Konoha's "God of Shinobi", had with ninjutsu), Mito Uzumaki (wife of the First Hokage, Hashirama Senju), Minato Namikaze (Konoha's Yellow Flash and the Fourth Hokage), Jiraiya of the Sannin (Konoha's Toad Sage), Kushina Uzumaki (Konoha's Red Hot-Blooded Habanero), and Tousen Uzumaki (Uncle of Kushina Uzumaki, and Uzushio's Multi-Blade for his ability to use multiple ninja arts simultaneously in conjunction with his own kenjutsu skills).

(Kurotsuchi's notes:Until the first printing of the very book you're reading right now, no solid foundation has ever been written or published that discusses or introduces this art. The reasons for obscuring this art are no longer valid (at least not in our opinion). This is why we are trying so hard to turn this art that has been obscured and has remained disorganized into a structured, organized discipline of study, and it's also why this book has been written and put into your hands. The rest of this art's…no, this discipline's…history is now up to us to write. And a glorious history it will be!)

What exactly is a "seal"?

As defined previously (in an admittedly oversimplified manner), a seal is a pattern that, when activated, serves a single function: to store something into something else, and to release what is stored within it in such a manner as to create a particular effect. What makes the previous definition overly simplistic is that there are single seals that exist, or that can be written, that have been given such complexity in and of themselves that many complex and advanced seal arrays seem to be quite basic by comparison. The differences in why one would preferentially use a seal or an array to do something will be discussed later, but suffice to say, regardless of the complexity of any seal, there are certain basic components that are common to all seals: all seals have nodes, and all seals have, or can be fitted with, ports.

A node is a specific and distinct pattern providing instruction for part of (or all of) the base of a seal. All seals are composed of one or more nodes. Where there is no node, there is no seal. As noted, the pattern must be distinct. This pattern can be a shape, a kanji, or even written text in common language. So long as it is written in such a way that an effect can be gleaned from it when chakra is added, the pattern is a seal.

Even people's signatures can serve as nodes on a seal. One case in point of this phenomenon is the method behind the workings of a summoning contract. The signer of a contract must sign their name in their own blood and provide the fingerprints of the hand that they will specifically be using to release the chakra built for the summoning. When they form the hand signs required to summon any of the summons on the contract, and then release the chakra that they have just molded, the seal activates. Depending on how much chakra the user molded into the technique, a summon of various size and power will appear before the user.

Another component that, while not necessarily built into any seal, can be added or fixed into any seal, is a port. Also called an insert, a port is what allows the seal to be connected to a conduit, thus making an array possible. The two types of ports that can be placed onto any seal are an input port, where the seal receives something coming in by way of a conduit, and an output port, where the seal sends something into a conduit to pass along to the next connected seal. It is important to note that any seal can only be fitted with one of each type of port. Two or more input ports can never be placed into a seal, nor can two or more output ports. If this is attempted, the seal will fail before it is even activated, thus rendering the seal completely useless.

Ports can be configured in a certain manner to increase efficiency of travel between the seal and the conduit connected to the port. An output port, for example, can be configured to either allow or deny "something" or "some things", such as energy, chakra, information, instructions, etc., to pass through the port into the conduit. Likewise, an input port can be configured in much the same way. Some more advanced seal masters (such as yours truly), enjoy not only configuring ports to allow or deny access to certain "things", but also configuring them to determine the rate at which something is allowed or denied access, thus adding even more versatility and functionality into a seal array.

It is important to note that seals do not change the nature of the objects that are sealed unless they have specific instructions to do so (and even then, there are limits as to how much of a change can take place), nor does the object or surface into which said item is sealed take on the nature of the sealed item. An example of this would be a Jinchuriki: tailed beasts are sealed into a person's body. The person does not become the beat that is sealed within them, and even the level of interaction between the host and the tailed beast would be constrained by the strength and complexity of the seal that is keeping the tailed beast at bay. More simply, a kunai stored into a scroll does not make the scroll a kunai, nor the kunai a scroll (while most would label this as "common-sense", the exact same principle applies to Jinchuriki and tailed beasts, and more often than not, this principle has been ignored when considering Jinchuriki).

And what exactly is a "conduit"?

A conduit is a connecting bridge between two seals, creating either a complete or partial seal array. The primary purpose of a conduit is to determine sequential order of activation between the two seals that the conduit connects together. In order to activate as part of a seal array, every seal must be connected, at least on one insert, to a conduit. It is important to note that a conduit cannot be connected to one seal and have no connection on the other end. If a single conduit like this exists within an array, the entire array will fail to activate.

A conduit consists of three components: the entrance, the passage and the exit. The entrance of the conduit is connected to the output port of the source seal, and allows "something", or "some things", whether it be energy, information, instructions, etc. (or any combination thereof – i.e. both chakra and information can be allowed), to enter the conduit. The exit of the conduit functions the same way as the entrance does, except that it is connected to the corresponding input port on the destination seal. Entrances and exits on conduits can be configured in a manner similar to the inserts to which they're connected, and generally speaking, greatest efficiency in communication between the conduit and its ports is established when the configurations match. Depending on the effect you're looking to create, however, a sealer may not always want the configurations to match. Someone may want to speed up or slow down the thing or things that travel across the conduit.

The passage of the conduit is simply the route through which the traffic that is output through the entrance from the source seal travels to the exit to be input into the destination seal. The only configuration of the passage that the sealer needs to bear in mind is the number of "types" of "things" being passed across it (for example, if instructions AND chakra were being passed across the conduit, the passage must be configured, and wide enough, to allow for the travel of both). The only other way that conduit passages can be given added configuration is through the use of flow regulator seals (explained in greater detail under supplemental fuinjutsu).

Fundamentals of Seal Construction

Having discussed what the basic components of sealing are, our attention can now be turned to how to use these components to construct seals and arrays. This is easier said than done, especially when creating your own seals. It's easy enough to take a seal that someone else had made and copy it (this is what most hacks who call themselves "seal masters" do when they create exploding tags), but this is of little to no value without understanding exactly what each part of the seal that composes the exploding tag does, and how it contributes to the whole seal.

There are two basic principles that a sealer should bear in mind when constructing a seal. The first, and most important, is the placement of nodes and ports that constitute the seal, and the effects that the specific placement of those nodes and ports will have on the seal as a whole. This is vitally important because this will affect every single seal you create, whether standalone, or part of an array. Understanding how and why nodes are placed where and when they are will greatly determine how your seal will function. This becomes more and more critical as the seal being constructed becomes more and more complex. It is the nodes that tell the seal exactly what to do. We'll take a basic exploding note that you can buy in any shinobi store as an example: one node stores fire chakra to help generate the explosion, one node stores condensed air so that when it's released, not only will the fire chakra be spread more quickly, but the condensation of the air will collapse, causing the rapid spread of fire chakra, creating a simulated "explosion", and when done correctly, there is one node that determines the direction and magnitude of the resulting explosion. The time-delay feature is actually a separate seal in an "exploding note array," as the timer is connected to the exploding seal by way of a conduit. There will be more on node placement in the next chapter, when we begin to discuss more advanced theory.

The second key principle that a sealer should bear in mind when constructing a seal (well, in this case, a seal array), is the placement of conduits that connect the seals in the array. The reason for this is because, as stated earlier, it is the conduits, and how said conduits connect the seals, that determine the order in which the seals will be activated, determining the final outcome and complete effect of the seal array. A single seal that is activated out of order in the array will either cause the array to fizzle out, or worse, have a completely different effect than intended. Many a potential sealer has met with disaster as a result of this seemingly simple yet critical oversight.

(Kurotsuchi's notes:When Naruto first began to teach me the art of sealing, I had a very close call with this. I was creating a barrier array, and I had connected two of the conduits to the wrong seals, messing up the order. When I activated the array, the barrier itself overloaded, and if it hadn't been for Naruto's quick action in releasing the array, I could have lost my hands, maybe even my life! I cannot stress to you enough the importance of proper seal construction and proper conduit placement; it could save your life, as well as the lives of those around you!)

Fundamentals of Seal Application

The methods and media through which seals can be applied are quite numerous, with more being conceived and implemented all the time. The three primary methods of seal application are: Using ink and a brush, carving or etching a seal into a solid surface, or simply using one's own chakra to write the seal. Anyone who would aspire to be a seal master should be proficient in using at least two of the methods listed above, though having some proficiency in all three methods will give the sealer a greater degree of versatility in how they can practice their art.

Any sealing student will first learn to apply seals using special chakra-conducting sealing ink and a standard set of seal-writing brushes. While fuinjutsu itself is not widely learned as an art, most shinobi learn how to create a few basic seals for day-to-day use. The most common seal that a shinobi will learn to use is a storage seal, usually painted onto a scroll. The seal would be painted onto the scroll using chakra ink and a brush or two, and would have some basic storage capabilities.

Certain items can be added into ink like this, or can even replace ink, depending on the type of seal you're painting or the effect that you wish to create. The most common example of a seal that would need an item added into the ink like this would be a blood seal. The seal can be painted either in a person's blood alone, or a sample of the person's blood can be added into the ink, and when the seal is painted, one or more of the nodes can be painted for the purpose of scanning the contents of the ink or blood used to paint it to look for specific characteristics in order to either activate or release.

Seals can also be carved or etched into a surface. Examples of this would be carving seals into a rock face, or etching seals into a katana's blade or hilt. While this is not as common as painting seals using ink, this method can be just as powerful if not more so for creating seals sue to the specific nature of the application and the nature of the surface onto which the seals are engraved.

Seals can also be applied using one's own chakra. Chakra can be molded into the sealer's finger, and as such, can be used to write seals into the air and project them onto something, or activate them in mid-air, exactly where they are. This is a very powerful and advanced method of seal application, and is a method that any aspiring seal master should learn to use.

When applying seals, it is important to note that the sealer's handwriting or painting style should be refined enough to produce clear, concise and distinct patterns. This is even more critical when applying conduits when linking seals into arrays. Conduits are smaller and thinner than seal nodes and ports, requiring much greater care to be taken when applying them.

(Kurotsuchi's Notes: You might find that your seals seem to work better or worse than someone else's. Even if you apply the exact same kind of seal as someone else, the only difference might be the handwriting of the seal applied. This by itself can determine just how effective the applied seal is, as well as things like how smoothly it functions, how quickly it executes, and even if it fluctuates while executing or releasing (you don't want to know how annoying it is for a barrier seal to fluctuate and fizzle out for half a second while a kunai is being thrown at you, believe me – this happened to me, and it was just long enough for the kunai to pass the perimeter line that the barrier was supposed to secure). Naruto and I both find, at least when we take the time to write or paint our seals, that sometimes his seals are more effective, and sometimes my seals are.)

Fundamentals of Seal Activation and Deactivation

At the most basic level, seal activation is as simple as focusing chakra into a seal or array. Likewise, seal deactivation at the most basic level is done by cutting the flow of chakra to a seal, in much the same way that you would cut chakra flow in your own body when releasing a genjutsu. While these two basic methods will suffice in sealing and unsealing in most cases, the idea of seal activation and deactivation as a whole is not quite so simple.

Seal activation may require certain types of chakra, or even a certain chakra signature, to activate. These constraints would be written into one or more of the seal's nodes. Many different constraints can be written into seal nodes that limit seal activation. Seal deactivation operates under the same principles, and similar constraints for seal deactivation can also be written into one or more of the nodes constituting the seal.

There are times when chakra must be molded in a certain manner in order to activate or deactivate a seal. While the chakra can be molded inside the seal itself, this method is very inefficient. The most efficient way to do this is through the use of hand signs that will guide the overall molding of the chakra, including the chakra nature, the rate of flow, and even the shape that the chakra takes on if this is what's required to activate or deactivate the seal. This gives the appearance of the sealer using ninjutsu, and it is this practice that gave rise to the term "sealing jutsu".

Once Naruto was finished with his impromptu lecture, he was flooded with questions about seals and their construction and application from those who listened, including Tsunade. Kurotsuchi got up and actually helped him to field the questions, explaining things from her point of view as Naruto explained things from his, giving their audience a much clearer understanding of the topic together than they would have alone; another one of those instances where their oddity as a couple shined brightly!

As they left the Hokage Tower for the day, they decided to stop into Ichiraku Ramen for dinner. Neither of them felt like cooking tonight, and Naruto felt that he had gone too long without indulging in the noodly goodness that Teuchi and Ayame provided to many a satisfied customer. As they stepped out into the streets, they headed in the direction of Naruto's favorite culinary establishment, all the while waving to passersby who greeted the pair.

Upon arriving at the stand, Naruto pulled back the flap, allowing his wife to enter and then following behind her. As they sat down, they noticed that Chouji and Ino were there. They sat next to the pair, greeting them to get their attention.

"Hey guys! Been a while!" said Naruto with his typical zest and gusto.

Both of them looked up from their meals in the direction of the greeting and adopted ear-to-ear grins at the sight off the Namikazes.

Ino began, "Naruto! Kurotsuchi! How are you guys?"

Kurotsuchi answered with a grin, "We're doing great, hon! Just got out of Grandma's office for the day and decided to come get some dinner! How about you guys?"

Chouji answered, "We're doing great, too! We started dating a week ago, and it's been a fun ride so far!"

Naruto congratulated Chouji with a manly handshake and a grin. Kurotsuchi, of course, squealed like a lovestruck fangirl and wrapped Ino in an excited hug, Ino returning the hug with just as much excitement.

Teuchi came up to Naruto and Kurotsuchi and took their orders. As Naruto and Kurotsuchi waited for their orders, they caught up with Chouji and Ino, talking about this and that. The Namikazes invited the pair to their home for dinner, to which the pair gladly accepted. Of course, when Kurotsuchi invited the pair to join her and Naruto on their next trek into the Forest of Death, both of them immediately "politely" declined with overly exaggerated grins and raised hands. Kurotsuchi could have sworn that she saw them both sweat a little at that particular invitation.

Thinking nothing more of it, they continued making small talk, eating their meals as they came up. Once Chouji and Ino finished, they excused themselves, wishing the husband/wife duo a good evening as they went on their way. Naruto and Kurotsuchi finished their meals, paid their bill and thanked their favorite ramen chef for yet another culinary masterpiece before heading home for the evening, both of them thinking ahead to the next chapter of the book that they were writing.

Chapter 2 done! Please read and review.