(Y/N) pov:

I was in bed protecting my new king as he hugged me while he slept. Since I didn't require sleep I stayed awake on watch to make sure no threats arrived to kill my king. I don't want to lose him like I did my previous family, this time I will eliminate any targets quickly and efficiently. He doesn't seem to like the sight of dead creatures so I must either get permission to kill or dispose of the body. My king began to move and groan until he opened his green eyes.

Izuku: Good morning (Y/N).

I hissed as a greeting. He got up and placed me on the floor while he went to the room of great liquid.

Izuku: You can head downstairs I'll be done in a second.

When he left I got up and waited outside the room he entered. He might take a while so I pondered on the past events of my life.

Even though my entire family was wiped out I'm glad it happened, because if it didn't I wouldn't have met Izuku. But my family's annihilation was do to my own incompetence and this time I learned from that grave mistake. Any and all threats are to be killed unless my king says otherwise. I just hope I'm strong enough to protect him.

I didn't notice the door open or Izuku looking shocked that I was still here waiting. He got over his shock and picked me up before going downstairs.

Izuku: C'mon (Y/N) I'm going to take you to buy a collar today. But first I think mom made us breakfast, so let's go eat.

What's a collar? He made his way downstairs following the scent of the delicious smell. When we made it to the origin of the smell we saw two plates on the table, and Izuku's mother placing some food in a bowl.

Inko: Good morning sweetie.

Izuku: Morning mom.

Inko: Your breakfast is on the table bring (Y/N) over here so he can eat.

His mother placed the bowl on the floor before Izuku brought me over to eat. I dont need to eat but they're watching me expectantly, so I opened my mouth and used my tounge to grab some of the food. It tasted heavenly so I took another bite and then another until it was all gone.

Inko:*giggle* I'm glad you like my cooking.

She rubbed my head before taking the now empty bowl while I sat next to Izuku's chair. I took this time to examine my body while I waited for him to finish eating.

Even in my shrunken form I still have my strength and defense from when I was still at my original size. But thanks to this form I should be able to climb walls and roofs now.

Izuku: I'm done! Oh can I have some money to buy (Y/N) a collar, please?

Inko: Alright just don't lose it.

She handed Izuku some strange objects before he put it in his pocket. He then went over to me and picked me up before walking out the door. As he was walking I got out of his arms and moved to cling on his back making sure my blades didn't hurt him. He was surprised at first before just smiling and continuing to walk.

Izuku: Are you excited (Y/N)?

(Y/N): *hiss*

Izuku: I'll take that as a yes. We'll be at the pet shop in a bit.

As he was walking I looked around at all the strange humans, some were even giving me strange glances. I remaind vigilant on the lookout for any possible threat. Whenever a human got too close to my king I hissed and brandished my tail at them. This always deterred the humans until Izuku told me to stop. We were walking through a location Izuku called a "playground" to get to the store quicker.

Izuku was cheerful and happy until we came across 3 other young humans. One had spiky ash-blond hair, another had small red appendages on his back, the last one had a purple hat. My kings heartbeat increased along with his breathing as he slightly shook. His change in behavior confirmed for me to remain cautious as these are potential threats.

Katsuki: Well, well, well, if it isn't Deku.

Izuku: H-Hey Kacchan.

Katsuki: What's that thing on your back?

My king backed up slightly giving me a nervous glance before answering the other human.

Izuku: He's my new friend I found him yesterday.

Katsuki: Well give him to me.

My king was shocked before questioning his intentions.

Izuku: Why would I do that?!

His question seemed to enrage the other human as his face showed nothing but anger.

Katsuki: Because a pet as cool as him shouldn't belong to a quirkless nobody like you!

That sentence seemed to have saddened my king as small tears began to form in his eyes. I used my blade hand to gently wipe his tear before nuzzling and purring into his soft hair. The vibrations must've tickled him as he let out a small laugh. But when the other humans heard his laugh they became more angry.

Katsuki: So you think this is funny Deku? You think I'm sort of joke?!

Before my king can respond the human somehow made an explosion in his hand, but he didn't seem injured or bothered by it. This human is dangerous I must deal with him to protect Izuku.

Katsuki: Maybe you haven't learned your lesson from last time. Looks like we're going to have to extend the lesson.

Last time? So they were the ones who harmed my king, I'll make sure they never harm him again. The one with red appendages grew giant wings before hovering off the ground, the one with the purple hat extended his fingers, while the angry one made more explosions. My king was now very frightened so I jumped off his back in front of the 3 humans and hissed. They weren't scared instead they laughed before the angry one gave an order.

Katsuki: Kill it.

Izuku: Kacchan no!

The flying one swooped down at me but before he could touch me I spewed acid in the air shocking everyone. Some acid landed on his wings melting through it causing him to crash and begin to cry in pain. That's one.

Katsuki: You bastard!

The angry one sent an explosion at me but I swiftly dodged. I might be strong but those explosions could still kill me if I'm not careful. I sensed something to my right and the one with the purple hat shot his fingers at me. I brought my blade hand up cutting one of his fingers off while injuring the rest. That's two now just the final threat to eliminate. I turned back in time to avoid an explosion to my head. I ran around him as he kept shooting explosions everywhere.

However one explosion was heading towards my king, so I ran at him at full speed just in time for me to push him out of the way of the explosion. But this caused me to be hit head on with it, the explosion singed my head and slightly hurt me. The human seemed to have thought I was down as he turned his attention to my king. But before he could do anything I swiftly got up and charged at the human ramming him into the ground. I aimed my tail at his neck as I pinned him down.

Katsuki: G-Get off me!

He's scared I can sense his fear as I opened my mouth revealing my tounge. As I was about to head bite him my king ordered me to stop.

Izuku: (Y/N) don't kill him!

I retracted my tounge but before I got off him I slashed his face with my tail leaving a small scar. The scar will be unnoticeable but this will serve as a permanent reminder if he tries to hurt Izuku.

I got off of him and went back over to my king as I climbed onto his back before rubbing my head against his.

Izuku pov:

I ran out of the park with (Y/N) on my back making my way to the pet shop.

I didn't think (Y/N) would attack Kacchan and his friends but I'm glad he likes me enough to defend me. It might just be because I fed him but he seems very protective of me. But how many quirks does he have? He's able to spit out acid, sharp tail, sharp blades for hands, and his skin seems strong enough to handle a small or medium sized explosive.

I was literally pulled from my thoughts by (Y/N) pulling me back just in time as a car came zooming by.

Izuku: Thanks (Y/N).

He just hissed and gave me a small nuzzle which I laughed at as it tickled, I then noticed I actually passed the pet shop. I quickly turned around before entering the pet shop ready to but (Y/N) his new collar.

Izuku: We're finally here (Y/N), come on let's find a collar you either like or one that suits you.

He hissed in acknowledgement before he began to look around as I moved around the store. After a while he used his tail to pick up a expensive looking collar.

I took it up to the cashier but on the way (Y/N) grabbed a dog tag as well.

This is probably going to be expensive.

I placed the items on the counter as the cashier rung them up and placed them back on the counter. I took out the money my mom gave me waiting for the man to tell me the price.

Cashier: 1,907¥ please.

I handed over the money before grabbing the items and walking out. Once outside I told (Y/N) to hop off my back for a moment to try on the collar and tag. I attached the tag on the collar before putting it around (Y/N)'s neck, making sure it wasn't too tight but not too loose that it falls.

(Y/N) pov:

This was the best moment of my life, not only was I able to defend my king in combat but I was also gifted a present from him. I promised I would protect him and I will keep that promise. No matter the threat's size, power, or status, they will all fall if they harm Izuku.

We proceeded to make our way home as I played with my collar on the way. The walk back was peaceful as we went through the playground once more, there were pieces of the child's wings, and the other childs severed finger. I quickly covered Izuku's eyes before spewing acid on the finger and remains of the wings. My acid was able to dissolve all the evidence of the fight in a few seconds.

Once all the evidence was gone I uncovered Izuku's eyes and went back to playing with my collar. After a few minutes we made it back home where Izuku's mother greeted us with a smile and another delicious meal. So far I say this day was great minus Izuku seeing me cut the childs finger off, and melting the other ones wings.

We finished dinner before Izuku took me upstairs to sleep. After the day he's had I can't blame him for wanting to sleep early.

3rd pov:

Over the years going by (Y/N) defended Izuku from all forms of threats and attacked the threats if Izuku allowed it (which he never did). Izuku also took notes on (Y/N) abilities just like he did with heros. Because in his eyes he was a hero, maybe (Y/N) can help Izuku on his journey to become a hero. Regardless what Izuku wants to be
(Y/N) will remain by his side till the end.

(Next chapter the book will follow the episodes.)