My Pretty Tough girl

Sonic was in depression since he tried to apologize to Amy for what he did. But Amy wouldn't hear it when she started dating Shadow. Though when Sonic started to have suicidal thoughts, something or someone dropped in on him (literally). He meets a familiar but pretty red female echidna (who is beautiful, tough, but also a slight hit head). Sonic started to fall for this girl. Who is she and why is she familiar to Sonic?