When I woke up, I realized that I was lying in a hard, damp place and slowly opened my eyes to take a look around, I looked up and saw a wooden ceiling while I heard a sound of rain outside. As I moved my head upwards a strong headache came to me, was this a consequence of reincarnation? Or had something happened because I was lying probably on a damp hard floor? I don't know.

The moment my head stopped hurting, I realized that my memories of the past and those of the body I reincarnated into merged, and I finally realized where I was. I was reincarnated in the worst possible place, in Amegakure. And in what period do you ask? In the middle of the 2nd shinobi world war.

I got up from the red damp ground and looked around me. I found three people in pools of blood, two of them were my parents who fought to defend our house with everything they had and ended up dying at the hands of a ninja who invaded our house. The ninja was on the floor breathing but unconscious.

Maybe it was because I was a child around 9 or 10 years old, or because I had never witnessed such a scene since I lived in a modern and peaceful world. But a wave of emotions like despair, dread, disgust and fear overwhelmed me.

With my legs still shaking I decided to stand up and checked my body for injuries, but apparently my wounds have all healed. After checking my body, I decided to look around to determine the level of danger I am in. I don't sense any other people around and could only hear the sounds of the heavy rain from Amegakure.

Still shaky, I decided to inspect the house. It is a rather precarious place with some small holes in the roof, some furniture scattered around what seemed to be the living room and a single room. I went inside this room and started to inspect around it and discovered that we had some supplies and a little money stashed away.

Returning to the room I came across a kunai lying on the floor next to the bodies of my supposed parents, I didn't feel a deep sorrow for their loss or anything of that sort, since the memories of my past life are greater than those of this life, so I guess I remained the same but with some extra information.

Soon after I heard a noise behind me and turned around, I realized that the ninja was getting up. But I couldn't do anything because I was still shaking and overcome with emotions because of the scenes that were totally new to me.

When the ninja stood, I noticed that he had a deep, horizontal cut in the middle of his chest and a hole in his shoulder, probably from a previous battle as he was already injured when he got here. Looking at his head I noticed that he was wearing an Iwagakure bandana and was probably still a genin since he didn't have a vest. After muttering something, he was making hand seals.

Realizing that soon the next one to drop dead would be me, I started to get desperate and had no idea what to do, in the midst of fear and despair my body acted on its own, as if by pure survival instinct.

I picked up the kunai that was on the ground and ran towards the injured ninja. Since he was hurt in the shoulder so it took him a while to make the seals, that's when I threw myself at him and hit the kunai in his belly.

We both fell to the ground, but I fell on top of him and kept piercing him more and more with the kunai, desperate to survive and not get killed by these shitty ninjas who invade civilians' homes.

After he stopped moving and stopped breathing, I got off him and felt my face wet. I don't know if it was because of the experience of killing another living being or because of the memories of this body or something else.

"Damn, that old fucker fucked with me!!!"

Suddenly a semi-transparent blue screen appeared in front of me with a message.

[finishing the system installation on the host].

 "what?"

[progress: 86%]

[progress: 91%]

[progress: 96%]

[progress: 100%]

[installation completed successfully]

"that must be the system that the old fucker explained to me"

[welcome to the demon slayer breathing system]

[due to death of a genin ninja: 10 Exp points were acquired]

[Level 1 has been reached].

[you have received the achievement: [kill your first ninja] for killing the genin ninja]

[you received rewards for the achievement [kill your first ninja] and for reaching your first level]

"wait?! I get Exp? And still killing ninjas?!"

Yes, depending on the strength level of the host or the strength of the ninja the experience gain is higher and thus the host will get stronger]

After I calmed down and wiped away the tears, I looked at the screen appearing above me, and began to plan what I would do from now on. First, I need to see how the system works and if I have status or something.

In my mind I thought "Status"

------------------------------------------------------------------------------

Race: Human

Name: Tsuna Hiro

Age: 10 years

Rank: Civilian

Rating: F +

Status: Tired and calm

Lv: 1

HP: 3/5

Exp: 0/20

Attack: 3

Defense: 5

Chakra: 0

Agility: 7

Resistance: 4

Acquired breaths:
N/A

Other Skills:

N/A

Achievements:

[Kill your first ninja]

Titles:

[another world]

-------------------------------------------------------------------------------------

"it really is like a Rpg"

Looking at my statuses I noticed something that caught my eye and asked the system in my mind "I know achievements give rewards, but do titles give anything?"

[can give some special effect]

"tell the {otherworld} effect"

{Otherworld: Title given to those who have come from another world and are blessed by the god of the multiverse.

Its effect is to: Leave the user's memory intact and make him immune to intermediate level genjutsu]

Blessed?! I was reincarnated in the middle of a war, in one of the most precarious villages for being the center of that war, I just killed someone in order to survive, and on top of that I was cheated by him before reincarnating. And you still say I was blessed?!!!

[yes, you were]

"AAAAAAARGH"

I was extremely outraged, but that's okay, there's no use crying over spilled milk. At least I won't suffer with the genjutsu proficient ninjas of Amegakure. So, I'll calm down and open my rewards, but first I'll change something.

"System, may I change form by which I call you?"

[whatever is most pleasing to the host].

"so, from today you will be 'wise' and I want you to call me Hiro"

[as host desired]

"Hiro!"

[as Mr. Hiro wishes].

"*sigh* all right, let's leave it at that. Now show me the rewards I received."

[Reward for reaching Lv 1: Chakra awakening and chakra control; do you want to apply it now?]

[Reward for achievement [kill your first ninja]: Basic Breathing; want to apply it now?]

I didn't expect such great rewards to come right away. It's even suspicious if you take into account how I was tricked when I first got here. But well, I'll take that as an apology from that old man. I was wondering how to unlock my chakra, but I think the problem has already been solved.

"apply the reward for Lv 1 and explain basic breathing to me"

[applying reward [chakra awakening and chakra control] ... successfully completed]

Suddenly I felt a warm feeling inside me and filling me all over, I think this is due to the chakra being released throughout my body.

Then I felt all the knowledge going into my head as if it had always been there, I can feel the chakra inside me and the knowledge of how to control it is already in my mind as if I had years of experience with it.

[Basic Breathing: A primitive form of breathing used to prepare Mr. Hiro's body so that it can support the use of the other forms and techniques of breathing; Generates a boost in all stats]

"Explain one more thing to me, since I awakened my chackra through a reward do I need it to use the breaths?"

[Yes, chackra is needed to use the other breathing styles, with the exception of basic breathing and sun breathing; the more chackra Mr. Hiro has, the longer he can use the breathing and the less effort is required].

Got it, so before anything else I have to find a way to increase my chackra reserve through training or some other means

"Right, wise one applies the reward now"

I don't know what effect this will have on my body right now, but this is the best way I have to strengthen myself and survive this chaotic war

[Applying the reward [basic breathing] ... successfully completed]

Instead of the knowledge coming straight to my head, it came in the form of a scroll in my hand. As I opened it somehow, I was able to understand everything that was on it and I can follow it step by step.

Now that it has come to mind, how do I get the other transformations?

"sage, explain to me how I get the other breaths."

[Every 10 levels a random breath will be delivered]

I get it, so the stronger the enemy is, the greater the experience, the more breaths I get, and the stronger I get. After resolving my doubts, I decide to start training, but first I need to give this body's parents a proper burial and get this ninja's body out of the house.

After burying them in a forest near my house, I placed flowers on their graves and went back to get rid of the ninja's body and see his belongings. Checking his things, I saw some weapons like kunais, shurikens and some explosion seals along with a storage scroll.

After I got rid of the body and got the blood out of the house. I sat down on a chair in the middle of the room and began to look at the parchment and analyze it.

After a brief glance, I decided to send my chackra into the parchment to see what was inside. When my chackra entered the scroll, a small explosion of smoke occurred making a *puff* and out of it came some dried meats, water bottles, a strange paper and first aid kits.