Sonic's mother was captured by Eggman in that show, and he got his brother and sister(Manic and Sonya) to come with him and using these weird weapons that doubled as instruments(and vice versa) to get her back. What they didn't know was they were even siblings until they all said "what happened to my mom?" "your mom is gone too?" "what does she look like?" "she's a roboticized hedhehog, just like my dad" "*gasp* we're actually in the same family? and i thought we were just all fast!" Then, they looked for Jules and Chuck. they were captured, too.