Scarlett 

Scarlett is an alien from an another world, you/Sora are also from another World. You/Sora have friends. Kayla is also from another world she is from the Cameratribe. Tiana is from a world where everyone knows what they are doing and they have very good technology. If they are your friends but One day you guys get called because Scarlett escaped  and you guys were sent it fix it but something happens ( this is like Sonic but my version )