Just like her owner, she has two puppets on her hands: the right one with a peach face and blue cloth for clothes while the one on her left has a peach face also, but pink cloth for clothes. She has green hair with some of it being pulled up in the front by a yellow bow. She wears a red overall like dress with a white shirt underneath and red shoes with white socks pulled up below her knees. Her eyes are blue and she doesn't mention her name to Amu or Rima.
As an X-Character, she looks like a typical one, black with a red "X" on their foreheads, but she has a paper fan, unlike her true appearance, which she uses to send most of her attacks through.
Amu and Rima meet Miyako when they were passing by a park and hear her comedy act. Amu looks shocked out of her mind, Rima looks thoughtful, and their Guardian Characters watch happily. Miyako ends her act by saying "King of Beasts Miyako-chan" and Amu asks Miki, who had begun to look bored at the end, what she had thought about it while Ran laughs like crazy, Su and Kusukusu joining in. Before Miki could tell Amu, though, Rima says it sucked. Amu looks at her and sees Rima was angry, scaring Amu. Rima and Amu go over to Miyako; Amu just for the sake of calming Rima down.
Miyako asks who they were, but Rima only points a finger at her and says Miyako had a long way to go. Miyako agrees half heartedly and asks who they were again, so Amu introduces them. Miyako introduces herself as Kizaki Miyako and Rima asks if that was a comedy set she had, Miyako surprised she had recognized it. She says she was going to do the Guffaw Grand Stage's "Welcome, Amateurs" audition, flipping some of her hair as does Rima like she had before in the doughnut shop. Amu asks if she was and Miyako says yes as it was the first step to realizing her dream. Rima aks about her dream, so Miyako says she wanted to be a comedian, to stand on the stage and make people burst out laughing. After some takling, Rima says she would train Miyako and the rest of the day they train and include Amu who didn't really want to join in.
The next day, Miyako is in the "Welcome, Amateurs" participants dressing room and says it wasn't good that she was nervous. The door opens and someone calls to Miyako. She turns and sees Amu and Rima, Amu who notices Miyako looked nervous. Miyako laughs, but Rima tells her when she got nervous to do straight man responses, so Rima and Miyako do. Miyako says she wasn't nervous anymore and Amu laughs before the door comes open and a person calls out to everyone. It was two men - one skinny, the other bigger - who say that Mustachio Jirou had come to see them and tells them to do the mustache cheer. Amu whispers to Rima asking what it was, but Rima doesn't know either. Apparently, it's just clapping your hands and saying "mustache" over and over as that was what the two men were doing before Mustachio Jirou appears. He tells them he hoped they all did their best and his toupee and mustache come off, the two men by his side say there went the legendary gag, but no one laughs or claps. One of the men notices this and holds up a sign that says "laugh" so the people in the room do so, though not really heartfully.
The bigger of the men points to Miyako and tells her to clap, but she only bows and starts to suggest what she would do if she were performing that gag, but Jirou gets mad and asks who she was to criticize his gag. She tries again to say that to make it funny she would do something, but she gets interrupted again by Jirou who tells her that a young person like her wouldn't understand his greatness. He bids the people a goodbye and leaves with the two men following. A person tells Miyako Jirou was the judge for the day and says it wasn't good. She looks scared, but Amu tries to tell her it would be fine. Rima agrees and tells her to do it exactly as she had trained. Miyako, still looking scared, nods.
In the audience, Amu is smiling and looking at the stage while Rima and Kusukusu are looking at what seems to be the program of the show. Two men come on stage and thank the audience for coming the the live taping of Guffaw Grand Stage and say that the show was beginning. They welcome the amateurs and announce the judge who, just like the man in the amateurs dressing room had said, was Mustachio Jirou. Finally, the amateurs come on stage, some making the audience laugh, others not before the announcers say that the next act was a young lady in the fifth grade and call out Miyako, King of Beasts. Amu says that it was Miyako's turn, so Kusukusu, Ran, Mik, and Su cheer her on. Miyako comes out from behind the curtain with a smile on her face and hears the bigger of Jirou's men say it was rare to have elementary students while the other says it should be fun. Jirou, looking bored, says that he had high expectations for her, scaring Miyako. Amu gets mad and says that him saying things like that would make her more nervous.
Miyako starts her act, but no one laughs, though Jirou does pull a smile at her, not for her act, but for her misfortune. Rima says that since Miyako was nervous, her pace was off. Miyako goes on, but Mustachio Jirou tells her it was enough because he didn't want to see any more of it. He tells her this wasn't the place to make summer memories, but she tells him she really did want to be a comedian. He tells her that being a comedian was harder than she thought, but she tells him she knew it was and that she still wanted to be one. Jirou tells her that because she was a girl, there were other things she could be and lists an example: a ballerina. She tells him she wanted to be a comedian and he says she could be a baker, but she says it was her dream to make people laugh. He says she could get married, but she says being a comedian was all she wanted to be. He smiles again and says she was a strange little girl, causing her to look up at him in shock with tears in her eyes. She runs off and in the audience Rima and Amu stand up to follow her.
Rima and Amu split up to look for her, but can't find her until Kusukusu says she found her. They look where she says and find Miyako sitting against a wall with an X-Egg floating next to her and her puppets on the ground with her. Miyako begins to speak, saying she knew she was weird and her X-Egg hatches, becoming an X-Character. It shoots an attack at the girls with its fan, but they run to dodge it. Rima tells Amu they should Character Transform and Amu agrees, so they unlock their hearts and become Clown Drop and Amulet Heart, respectively.
The X-Character laughs and sends another hit, but Amu blocks it with her poms-poms and calls to Rima who uses Juggling Party. The X-Character dodges them and sends another attack, but they jump back this time to avoid being hit. The X-Characters attack hits some bamboo sticks, making them fall and they knock Rima down. Su and Miki go over to her and Su asks if she was okay, Rima saying she was. The X-Character says "weird" over and over until Amu tells her it wasn't weird, stopping the X-Character. She goes on and says that Miyako was shining so brightly and having lots of fun. She remembers Miyako saying it was the best when people were smiling and her saying her dream was to be a comedian and make people laugh. Amu says to believe in your own dream and that it didn't matter what other people say. She says Miyako's dream was hers alone and that the people who made fun of it were the weird ones.
The X-Character gets mad, but before it could do anything, ropes come forward and bind it; Rima having done it using Tightrope Dancer now that she was standing again. Rima tells Amu that it was her chance and Amu nods before locking onto Miyako's negative heart and using Open Heart. The X disappears from the X-Character and Miyako's Guardian Character appears, saying "King of Beasts Miyako-chan." Amu and Rima smile at each other before the Guardian Character says she was sure Miyako would make a great comedian. She says that it was Miyako's wish to make people laugh that gave birth to her. She thanks them for coming and goes back to her egg and into Miyako. Miyako's eyes open and she wonders what happened. Rima asks her if she was okay, and she says she was as the bad feelings she had been feeling before were gone.