|“||Don't you think before this year is over... that you may as well try something supernatural related? This spell may not be a bad opportunity.||”|
—Miyako Hayakawa, Corpse Party: Another Child 1 (Chapter 0)
Miyako is a teenager with short brown hair and brown eyes. She is wearing the Satsukiyama Academy school uniform consisting of a brown double-breasted jacket, a white sailor shirt with a black trim, and a black skirt with knee-length black socks and black loafers. She is known to have a dolphin charm attached to her cell phone.
Miyako is friends with Erina Yuzuki and Yuma Okita is a part of their clique. Miyako was more or less a bystander in bullying Tamaki Minase as she would neither join in with Erina & Yuma, nor put a stop to it. However, while trapped in Heavenly Host, she apologizes for what they have done to Tamaki.
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Miyako is the one who originally suggested Erina to make the Sachiko Ever After ritual and tells her how to do it.
While trapped in Heavenly Host Elementary School, she is found unconscious by Tamaki. While looking for their classmates, they stumble upon a splattered corpse and ran away panicking. After calming down, they meet an injured Yui Shishido who reveals she's a teacher at Kisaragi Academy. She tells them about the ritual and never being able to meet their friends again. They are separated from the teacher after an earthquake collapses the floor. In a classroom, they meet Shinichi Yanagihara and five other classmates: Kana, Minoru Hasegawa, Noriko, Yamazaki and an unnamed fifth student.
Miyako decides to tag along with Tamaki and Shinichi to look for Yuuma Shindou and Erina, leaving the classroom and five classmates behind. Shinichi shows the two girls that the windows are unbreakable and thus they can't escape from the school. Soon after they heard Minoru scream. As they rush back to the classroom, they find four of their classmates dead and witness Minoru's head being ripped off from his body. Tamaki feels something dangerous in the classroom and prompts all three to run away. As they try to recover their breath, Miyako breaks down in tears at the thought of having lost her friends. However, she doubts that it's Tamaki's fault when she blames herself for having performed the ritual, remembering how she prompted Erina to making it.
As Tamaki leaves to use the toilet, Miyako reveals to Shinichi that she and the rest of Erina's clique saw the spirits 6 months before. She then refuses to confirm that they have been bullying Tamaki. As she goes to look for the latter in the toilet, an earthquake shakes the school and they hear an announcement on the school's broadcast system saying that school is over, and all remaining students would never be able to go home again.
After they wander in the halls for a while, Miyako tries to use her cell phone, but it does not connect. As Tamaki notices the dolphin charm attached to it, Miyako mentions that it is a gift from Erina. She then apologizes to Tamaki about the bullying they made her go through.
The three find a library and try to look for clues there. They find a newspaper article that reports on the murder case that happened at Heavenly Host Elementary School, and how it's connected to the school's curse. As Shinichi tells the two girls to sit down and rest, Miyako reveals that Erina told her about Tamaki's secret psychic abilities.
At that time Yuuma, Erina and Yuma find a corpse, who is reduced to a skeleton, and impaled on some debris. Erina spots that the corpse is holding a phone with a charm that she gave to Miyako on her birthday and understands that this corpse is, in fact, Miyako.
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Later, while Miyako looks through the rows of books she spots a girl wearing a black dress staring at her from the other side of a shelf and screams. As Tamaki reveals that she saw her before, Miyako remembers and states that the girl's name is Saki Akagiri. She then gets up with a possessed expression and runs away. Shinichi and Tamaki run after her to find her in a dark classroom, surrounded by the ghosts of Yuki Kanno, Ryou Yoshizawa and Tokiko Tsuji. As Shinichi recognizes them as the murdered children mentioned in the article before, Yuki declares that she'll skin Tamaki for her collection. She is stopped by the girl in black however, and with an annoyed glare, closes the door to the classroom behind her. As Shinichi tries to open the door in vain, Miyako finally comes back to her senses only to see Yuki and Ryou standing over her with a sadistic expression.
- Miyako's corpse was shown before she was killed, but the next chapter showed her actual demise.
Corpse Party: Another Child