Corpse Party: Another Child (コープスパーティー Another Child (アナザーチャイルド),Kōpusu Pātī: Another Child (Anazā Chairudo)?) is a Japanese manga series written by Makoto Kedouin, illustrated by Shunsuke Ogata, and published by MAG Garden from October 2011 to March 2013. The manga is an spin-off which takes place during the events of Corpse Party and also feature cameos from the Corpse Party cast.
All seventeen chapters in the series was collected into three volumes, with the first volume released on March 10, 2012, and the third volume released on February 9, 2013.
With their school shutting down for good, the students of a small town were heading for different directions in life. For Tamaki Minase, who was staying in town to find a job, it might be the last time she sees her crush Yuuma Shindou, who is moving to the city to attend a new school. She asks him to do a little prayer that is supposed to help people cross paths again even if they become separated. But her classmate, Erina Yuzuki, overhears their conversation and, out of jealousy, decides to ruin her plans by inviting their entire class on what was supposed to be an intimate spell.
As soon as the charm goes off, the ground splits in half, swallowing the entire class and, when they wake up, they find themselves in an old school campus. Unable to find a way out, they wander the corridors, trying to figure out where they are. But it seems that the building isn’t as abandoned as they thought it was and, in fact, something evil is lurking in the shadows. 
Saki Akagiri A mysterious girl's spirit who wears a black gothic lolita dress.
Spoiler Warning!: Spoilers for Corpse Party: Another Child follow
Corpse Party: Another Child 1 コープスパーティー Another Child 1
March 10, 2012
Chapter 0; (Chapter 0;) Introduces the main cast and tells us about the school closing and the relationship between Tamaki and Erina.
Chapter 1; Sachiko Ever After (Chapter 1; 幸せのサチコさん) Everyone are having a ceremony on the schools closing. After it Tamaki and Yuuma are alone together and talking about the charm. Erina, along with many classmates join them and all of them do the Sachiko Ever After divided into two groups. An earthquake strikes and sends them all into Heavenly Host. Tamaki wakes with Miyako and explore, seeing the corpse of Mayu and encounter injured Yui.
Chapter 2; An Omen of Despair (Chapter 2; 絶望の予兆) After another earthquake Yui and the two girls are separated, so Yui leaves them behind, telling them to be safe. The girls then enter another classroom, finding Shinichi along with 4 other classmates. Shinichi goes about with the two girls and soon they hear the scream from the classroom. After entering it they see that 3 of the students were brutally murdered, the last one sitting on the chair. He starts laughing and his head is ripped in half.
Chapter 3; Encounter (Chapter 3; 邂逅) After Tamaki mentally breaks down, being responsible for getting everyone involved into this. Shinichi calms her down. While walking around the school, Tamaki goes to use the lavatories, encountering the spirit of Seiko being hanged and the mysterious girl with the lolita dress. The girl attacks and seemingly kills Tamaki, but it is just the illusion. The girl then speaks with Tamaki, but Tamaki can't hear her. Miyako comes in, checking on Tamaki. After they walk out, an earthquake hits the school.
Chapter 4; Yuma (Chapter 4; 由真) Point of view changes towards Erina, Yuma and Yuuma, who all ended up together. They all find the corpses of their classmates, now skeletons, and they get really worried. After some walking around they find the entrance to the school and Yuma goes in to check it out. She finds the three children spirits playing with as corpse, but escapes before they notice her. After being interrogated by Yuuma, she lies about Tamaki being there. He runs in, as Yuma prepares to block the door, so he could meet his demise.
Chapter 5; Children Spirits (Chapter 5; 児童霊) Yuuma, inside the entrance encounters Yuki and Ryou, who try to kill him. By dodging them, he reaches the way he came in, only to realize that Yuma blocked the way. The door opens, revealing Tokiko, who points him where the other two are. After Yuuma reunites with the two girls, Yuma and Yuuma have an argument, which is interrupted by Erina finding another skeletal corpse of their classmate. Erina screams, saying that it belongs to Miyako.
Corpse Party: Another Child 2 コープスパーティー Another Child 2
August 10, 2012
Chapter 6; Dependence (Chapter 6; 憑依) Shinichi, Tamaki and Miyako all enter the reference room and look around. Miyako and Tamaki have a conversation, which is interrupted with Miyako seeing the ghost of the mysterious girl, while panicking, Miyako is possessed and runs away. Inside the classroom that she ran into, are the three ghost kids. Yuki threatens Tamaki to rip out her face and add to her collection, but after seeing the mysterious girl, she stops and blocks the door so they can torture Miyako in piece.
Chapter 7; Naho Saenoki (Chapter 7; 冴之木七星) Yuma, Yuuma confort Erina, who despair over finding her friends corpse. They all enter the inrimary, where Erina goes to rest, locking herself out from the two. Yuma and Yuuma have a conversation. In the mean time Shinichi and Tamaki enter the infirmary and find Naho along with their last missing classmate, Mayuri. Naho explains to them that the two groups are separated by the closed spaces and that they can't meet up. Yuuma, while exploring, is being stalked by Tokiko.
Chapter 8; Outsider (Chapter 8; 異分子) While Yuuma encounters Tokiko, seeing the illusion of his death, he throws her aside. She comes closer to him, not meaning any harm and explains to him about the girl Tamaki brought along with her and about her two fellow child spirits. In the mean time Naho continues explaining to Tamaki and Shinichi about the closed spaces and other things. She then leaves, leaving Shinichi, who heads for the lavatories, Mayuri and Tamaki behind. Mayuri then mocks Tamaki.
Chapter 9; Suspicion (Chapter 9; 疑心) After being mocked by Mayuri, Tamaki yells at her and runs away, looking for Shinichi. She trips and realises the mysterious girl is right behind her. They talk and the girl wants Tamaki to join her. Tamaki almost accepts, but Shinichi stops her. In the mean time Yuma and Erina both enter the third floor, where Yuma, while running trips.
Chapter 10; Promise (Chapter 10; 約束) After the cabinet falls on Yuma's foot, Erina tries to get it off. Seeing as it's help by some strong force, Erina runs to get Yuuma's help. In the mean time, the two children spirits appear and mock Yuma, who yells at them. The kids then smile menacingly. Erina finds Yuuma and both go back to the place. In the end, Erina finds Yuma in the classroom, who doesn't respond. After that, it is revealed that she was cut in half, already dead.
Chapter 11; A Ray of Hope (Chapter 11; 一縷の希望) As Erina despair over her best friends death. Yuuma and Naho, who appeared behind them, goes to a classroom. In the mean time Tamaki and Shinichi talk and Shinichi trips, falling into a hole. He grabs on the ledge, but gets stabbed in the foot by the two ghost kids. After looking up he sees the mysterious girl behind Tamaki and the ledge he was holding on to breaks, making him fall to his apparent demise. In the mean time, Yuuma finds out that Erina lost her sanity.
Corpse Party: Another Child 3 コープスパーティー Another Child 3