He Was a Normal Boy, Until He Found Naban

Caden is a normal boy with a normal life- normal brown hair, normal copper eyes, normal little sister.  Until he finds a secret world under a pile of leaves, he finally has a secret to keep.
His dad is shoveling piles of leaves in the front yard and goes inside to take a break.  Caden had been outside with him and had wanted to jump in one of the leaf piles his dad had made, but Caden had known that his dad wouldn't let him ruin all his hard work. So when Caden's dad went inside, Caden picked the biggest pile of leaves and jumped in.  While Caden was still buried in all of the leaves, his dad came outside to shovel the leaves again.  Caden had no choice but to stay under the leaf pile, while his dad shoveled barrels and barrels of more leaves on top of him.  Caden was worried that he was losing all of his air, so he had forced himself to start digging out.  But, halfway through the digging, the ground disappeared from below.  The hole closed up and the leaf pile remained above ground, while Caden went tumbling down into the hole.
Caden gets used to all of the people in the secret world called Naban, learns he cannot tell anyone about Naban, or else someone could easily try to destroy Naban, and Naban is a secret world that is not supposed to exist, so the people who invented all of the secret world will find out and, everyone in Naban is toast.
Everyone who lives there either has copper or silver eyes.  Copper meaning likable and sweet, and silver meaning strong and, let us say, not always likable.  Caden meets two friends he grows to know very well, Petunia and Albert, who both have copper eyes.
He meets another girl there who seems a little suspicious, Aiban, who has silver eyes.  She sneaks out of conversations sometimes when people aren't paying attention to her, and after she sneaks away, you will not see her for hours and hours.  Nobody knows what she does during those times.  But the next day, something will be missing, like a jewel or something else that is valuable.  And the first suspect is always Aiban. But she never gets arrested.
Caden, Petunia, and Albert want to find out her secrets.  So, one night, they sneak out of their houses and meet at Aiban's house.  They walk around for awhile, looking for clues outside.  In the window well they see a light on in the basement.  Caden, Petunia, and Albert peek into the window well and Aiban is sitting in a chair with a mask on making some sort of invention.  Soon after that, they find out that that contraption was going to be used to destroy the world of Naban.  Aiban was sent here for that reason.  Aiban had planned that she would destroy Naban by moving the Rint (the moon in Naban, which is actually more like a meteor) towards Naban.  The Rint would hit Naban and the world would be distinct.
Caden, Petunia, Albert, and Mabel (another girl Caden met) have to go on a journey into Naban space to save the Rint from hurdling towards Naban.