You are a hedgehog, just like Sonic, which he didn't know there's more like him

You came to Earth through a ring portal, you sensed the energy of Sonic's electricity and speed, you start walking in a town called Green Hills

After a while, you are fighting Robotnik which is Eggman which you encountered while exploring, Sonic came to help you!

Sonic: Fear not! I'm here to-

Sonic noticed you are like him, a hedgehog in this world