The Mysterious Twins

When two students turn up at Chaos High in Emerald City, some students find them familiar, but don't recall from where

The two students are hedgehogs, they are twins, one is a green male hedgehog with sapphire eyes, by the name of Emerald, the other is a blue female with emerald eyes, her name is Sapphire

But they hide many secrets, one go which is that 'Emerald' and 'Sapphire' aren't there real names

Shadow and his brother and friends notice there odd behaviour and plant to find out why