You don't have to make these changes, as they are only suggestions. So it's all up to you.
They both had long, raven-black hair that glistened under the mooon's amber gaze.
you spelled moon wrong here.
"I'...m...afraid not...", she didn't want to accept that she let her sister down.
Doesn't make sense. She doesn't want to accept the fact that the let her sister down? Is that it? Try saying: she didn't want to accept the fact that she too was scared. Read the above quoted sentence again slowly, loudly and you'll see what I mean.
"Put it down! It might be poisonous!" Ame knocked the plant out of Imitsu's hands. When it hit the stone floor it smashed, as if it were glass.
Just previously they were outdoors, now they are all of a sudden indoors because the flower hits the STONE FLOOR. You haven't said anything about them being indoors or coming inside. You might want to add a sentence or to to explain, or tell you readers about them coming to the place with the stone floor.
It had [s]very[/s]dark red bricks and no windows or doors, just a hole in the roof.
Take out the Very. I understand what you are trying to say here but it's unnecessary and sounds awkward.
"We've got to. It's the only way, Gr-Grandma isn't here to tell us everything will be okay anymore", she replied, attempting to be courageous.
What are you trying to say? We WON'T be ok anymore? We'll be ok. I'm confused. Read your sentence through. Doesn't really make much sense, does it?
"Is that a new one or the same one?" Imitsu asked, extremely confused.
wholly baffled? Sounds nicer
"It really wants to doesn't it? Let's go!" she kicked a black metal door open bravely...but there was quite a drop.
how about: "It really wants us to, doesn't it?" She bravely kicked a black metal door...
You are taking things too quickly here. Stop and explain things a bit. Are they getting certain vibes or feeling from the plant? How come your character feels as if the plant wants her to do something. Explain what she's thinking, how does she know the plant wants them to do a certain thing.
The moon seemed to be always watching...anything they did was watched...everything they said was heard...
Just really liked that line!
It started as a messy, dark city then began to unravel into a strange place with grey stone walls and green ooze on the floor.
Elaborate. Explain the feelings the sensation. It more exciting and enjoyable then.
In the building it was disturingly quiet and dark.
Spelling. Disturbingly.
The only light was throughthe tiny holes that were now getting smaller and smaller.
space bet wen 'through' and 'the'.
She could read it now, "Correct! This was a test to see if you were worthy of continueing the Ochu plants' existence. You have impressed me. I am the last one and very lonely...could you plant this seed in a safe place? It would mean so much to me," she read.
Spelling. 'Continuing'.
Take out the READ either at the beginning or at the end. It sounds awkward.
For example. She yelled loudly, "Steve some down here!" she yelled.
Sounds awkward doesn't it?
---that's pretty much it. I really liked the beginning of you story though. It was descriptive and not too fast. Try and stop and elaborate on the surroundings, the feelings while you are writing.
Hope I wasn't too harsh. I realize that you wrote this back when you were 12. This story has a lot of potential. See if you can re write it. If you do post in on YWS and let me know.
-icy
