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Magical Pencil

We had another dismissal time. Here I am, walking down the busy streets without my sister by my side. I just miss her smiles, how she took care of me when I was young; and the way we argue on things because of my hostility. While I was walking, I noticed an old magic shop. I was in the same place where my interest was captivated. Out of the blue, events started flashing back to my mind. My eyes were caught by a charcoal pencil covered strange symbols. I was wondering what magical spell it holds. With this in mind, I bought that odd pencil and kept it in my pocket. As I reached home, my attention was distracted and I forgot that strange pencil. The day passed and school day began. I was at the middle of my art class. Our course for the day is to create a pencil sketch of a picture of a bowl of fruits. While I was drawing the picture, my pencil broke. I had to finish my work so I placed my hand inside my pouch. Groping for another in my pocket, I felt a solid object. I pulled it out and saw the pencil that I bought from the magic shop.
I made a mistake whilst I was drawing. I rubbed out the mango that I had drawn. At the same time as I was rubbing it out on my sketch, I noticed that the mango in the picture was gradually disappearing. I was astounded by the pencil’s magic.
I brought it home. After school, as I come into the street in front of our house, I saw a strange sight. My sister, whom I hate, was climbing a large tree on the front lawn obviously trying to save her pampered and spoiled cat. I found my hand was grasping the magic pencil, a strange compulsion gripped me and pulling out my sketch pad I quickly sketched the cat, and as quickly erased it.
The cat just out of reach of my sister disappeared into thin air. My sister was so frightened. She scram led down the tree and ran into the house and to her room.
I saw my mother beside the door. She was leaving for her job. “Stay put, don’t be a burden to your sister”, mother said to me. I went inside the house and saw that there was mess everywhere. My sister came down the stairs and said, “Clean up the living room, and after that clean your room”. I used my magical pencil to finish the work. I finished it ahead of time, so I turned on the television. While my sister was playing her piano, she heard the noise of the television. She scolded me for not doing my assignments. Using my sketch pad I drew and I erased her piano. My sister was shocked, she ran to the phone and called my mom and reported the disappearance and my thoughtlessness. While my sister was talking with my mom, I decided to erase her so that she’ll be gone forever. I missed my sister because she’s my only sister. I decided to erase myself so that I will reap my consequences. After I erased myself I was drifted to a place that I was not familiar with. The place was like dome full of things. The things were scattered all around. I saw the piano and all the things that I had erased. But I didn’t saw my sister, instead I saw a pirate. The pirate was grubby all over; his face was as fuming as a lion. He chased me throughout the dome. I drew the pirate and tried to erase it. The pirate temporary disappears but suddenly appears on a different position. I also tried to erase myself but I was transported to a different position. An idea formed in my mind that the person who holds the supernatural pencil will not be wiped away forever. Temporarily, I saw my sister. She was impounded on a large steel cage. I erased the cage and saved my sister. Now my only problem is how to get out of the dreary place. In a little while, I thought of an idea. I drew the dome and embrace my sister as I erase the picture. The dome was emptied an all I can see was a pallid place. But in the middle of this empty place we saw a door. We rush to the door, assuming that it was the way out. As I we woke up, we saw our house. We were happy that day and I reconciled with my sister. I realized how she was so exceptional to me. From that day onwards, I was a changed person. And now that my sister is far away from me, I just want to bring back the times that I had lost spending with her. After two months my sister was married and left our house. I really wish I can bring back those time. I guess, I would buy a time machine from this shop. Oh well, never mind, it may have a consequence. I looked into the sky and thanked God for what he has done in my life.

Sort out the grammer, few more paragraphs, few less 'I's.
Content-wise, pretty solid.

Also, you may want to try for a stronger first line, something to grab people's attention, and the sense of time is a bit muddled.

Since you’ve asked for help I’ve read through this and tried to give you a few helpful ideas without trying to be overly critical.

First sentence begs clarification. I will agree with Rosalind there. Another dismissal as opposed to what and from what – how many dismissals does one get from something – essentially what were you dismissed from – school? Your tenses are mixed up throughout the story. The story’s a little monotonous and too sober throughout; the tone might be a little more playful regarding the magic pencil escapade perhaps. I think something like that’s needed or either scariness or something that would add to the unusual adventures to break up the dreary tone of the story. I like the droning seriousness of the beginning though because it leaves us wondering why you miss her and complements the ending quite nicely. But again what is it that you want to depict? What do you want the reader to feel and think?

When you say the mango disappears I wondered what you meant and had to reread it so maybe you could explain that it was the real mango in the real fruit bowl that disappeared along with your drawing. And wouldn’t that freak you out a bit? Would anyone else notice? Realistically you weren’t alone and someone had to notice and wouldn’t that cause some type of reaction? Also, if your sister’s cat disappeared and she was so frightened I would think she wouldn’t just go play her piano and order you around. What would her actions be after seeing something like that happen and especially when the piano disappeared? What would your reactions be? Terrified, scared, shocked, speechless, confused, angry at the implausibility of it? So that I would flesh out a bit.

I do like that you realized the error of your ways towards the end but I would put a little more emotion in that realization rather than merely stating you wanted to reap the consequences, after all it’s a rather heinous crime just wiping someone out whether with pencil or butcher knife. In my personal opinion the story will be a rather good short story and perfect for children really if you revise it entirely by adding clarification and more emotion. It’s a good idea, good start, middle part might need a bit of an overhaul but it’s a good ending too. I hope this wasn’t too harsh and helps.

I agree with Darlin's comments. Also, I was thinking about it, and--forgive me if I'm way off base here--I think I've either seen or read a story like this before. It might have been a children's book, or a Disney Channel movie or something. Just letting you know.