Allie and Kate are Grojband's adorable groupies, and are the very best friends. They are seen doing everything together, a large portion being showing their affection towards Grojband. They usually squeal over Grojband and are in love with every single member of the band mostly Corey.
When Trina drives Grojband out of the garage, Allie and Kate appear and begin squealing in affection for Grojband. However they immediately dive out of the way as Trina doesn't stop the car. The two of them start texting each other, about how excited they are for almost getting run over by Grojband. Later on they work together to sell Grojband merchandise and make money for Corey.
Allie and Kate are both excited about the arrival of Cherry Grapestain and excitedly tell Corey, but after getting grossed out by Kon's callouses, they abandon Grojband and go off to see Cherry instead. Later on as Grojband perform Cherry Cherry, the two girls are seen dancing to the music.
Corey assigned Allie and Kate to a mission to steal Trina's toy from her room. Allie and Kate both enter her room with spyware and bungee equipment, but get attacked by the security system. They both scream in fear as they cling onto each other for protection. When they return, Kate is seen dragging Allie with her to the Speed Circle.
Allie and Kate were spying on Corey together and they saw the band come out wearing mullet wigs. Kate questioned it at first, but Allie told her that it doesn't matter and they should just squeal and so they did. When Corey assigned them to a mission, they both looked at each other and squealed. Later, they helped each other put a magic cover over the end of the tube.
Kate and Allie both went to Candy Jam's concert together. They both told Corey about their love for Candy and how she had tapped into their feminine side. They told him about how they loved her music and everything that it did to them. They were also seen sitting next to each other while Kin and Kon put on a scary show. After the show needed, Allie said to Kate "That was lame." When Candy advertised her new line of makeup, Kate and Allie squealed in joy. Allie said to Kate "Finally we can be as true to ourselves as Candy Jams!" and they ran over there and put on makeup together. Kate was applying lipstick and Allie was powdering her face.
Allie and Kate both helped each other make a propaganda to get Grojband back into the city again.
Allie and Kate built a shrine to Grojband and mourned over his loss. They both stood by the shrine together and put their arms around each other as they slowly swayed back and forth and had a moment of silence. Corey revealed himself to them and told them that he want really dead. Kate accused them of being a cover band. At first, it seemed as though Kate believed him, but after hearing Kate's accusation, Allie went along with her too and they both walked away. They also attended Grojband's big return concert together as they were both heard screaming "We love you Grojband cover band!"
Kate and Allie are overjoyed to receive a Valentine card from Grojband, but when they open it they hear Trina's scream of rage, it leads them to separate as friends. When Corey comes over holding up the card playing the new song Love it's in my Heart, Kate and Allie make up and hug each other.
Kate and Allie both revealed to have built many things dedicated to Grojband. They did things such as building an exact replica of the garage only backwards as well as a shrine to Grojband. They also set up many traps for Corey and the band such as aroma therapy in Corey's kitchen, captivity waffles, and a dungeon in the closet.
- Although Kate and Allie are Grojband's biggest fans, they have been shown to be even bigger fans of others celebrities in the show, and will abandon their loyalty to Grojband if they appear.
- Kate and Allie's shirts match only their colors are swapped.
- Kate and Allie's matching shirts match Kon and Konnie's.
- Although Kate and Allie have an undying love for Grojband, it is implied that they might also be fans of their rival band, The Newmans.
- Both Kate and Allie are similar to Sierra from Total Drama, as they are loony, obsessed fans of someone (Kate and Allie of Grojband, and Sierra of Cody). They are also similar to Katie and Sadie, as they're best friends with each other, are rarely seen without each other, and they both squeal a lot.
- Their first names are the same as the lead characters of the sitcom "Kate and Allie," while their last names are the same as the last names of "Kate and Allie" directors Bill Persky and Linda Day.