|Alternate Names|| Yuuma Kashiwagi (Real Name)|
Ataru Marble (In Third Season)
|Family|| Shin Kashiwagi (father)|
Chitose Kashiwagi (mother)
Yuuma Mukai (older twin brother)
Yuri Kashiwagi (younger sister)
|Occupation|| 2nd Years High School Student|
Real Account Member (Season 2-onward)
6th Death Game Organizer of Real Account Tower
|First Apperance||Chapter 1|
"No... As I said... I decided to fight! But what I promised myself... is to fight without killing anyone! I've killed a person before... and I never want to do that again..."
– Ataru Kashiwagi when answering Aiji Hoshina's question, Chapter 10
Ataru Kashiwagi (柏木 アタル, Kashiwagi Ataru), or known by his real name Yuuma Kashiwagi (柏木 ユウマ, Kashiwagi Yūma), is the protagonist of the first part of the story, and one of the antagonists in second and third part of the story. He has a younger sister, Yuri Kashiwagi.
Ataru is of an average height and build, with gray eyes. He has short black hair with bangs, and a cowlick towards the back.He is shown wearing his school uniform, which consists of a dark blue button-up shirt with a black tie, and gray plaid pants.
Ataru is the real Yuuma Kashiwagi and twin brother of Ataru Kashiwagi. During their childhood, the twins are always changing their position role to plays the football. The twins were enjoys to playing football so much, until one day an accident happened to Ataru. Yuuma don't want everyone to sad at Ataru's death so he faking himself and acts as Ataru.
Since the incident, "Ataru" believed himself "killed" his older brother (Thought it's later revealed that it's Masahide Eniguma and Marble who killed "Yuuma"), "Ataru" is also shows to lost his ability at playing footballs.
Chapters 1-10 (First Season)Edit
Ataru first appeared at Chapter 1, he back to home from school. Ataru's sister, Yuri Kashiwagi, is waiting for him and she was cooking. Along with Yuri, Ataru is eating lunch at home. Yuri noticed and said that Ataru have no friends but he deny it and said he did have a friends, though it's just a lie. Ataru thinks that compared to in real life, it's way easier to finding friends in the internet, he believed that these friends are actually care about him. Soon, Ataru's smartphone was flashy which caused him getting transferred into internet world, Real Account world.
After being transferred into Real Account World, Ataru wonder where were he and saw Marble arrived. Marble revealed there's a small game to plays now, to seeing how many followers still want to follow the players even if they will be kills soon. Ataru calling Yuri and tells her don't follow him due to he don't want she die with him, but Yuri disagreed with it and said they will always be together. After lessening Yuri's word, while Ataru think she should be follow him but he still wanted to block her to save her life. After Ataru blocked Yuri, he noticed there's still one follower followed Ataru and survived. After the mini game is finished, Ataru showed to be angry and hopes he can give Marble an punishment.
Soon, Ataru joined the first death game, "No Answer". During the first game, Ataru keep thinking if his face should be "○","△" or "×" while watching how the other players giving marks. When Marble noted that Ruriri Ichijou is also joined this game, Ataru think that Ruriri is beautiful, though after Ruriri's actual face was showed to all players Ataru was surprised at how inaccurate her user icon and actual face look like. When Ruriri is about to die, Ataru saved her and said to her followers that the face isn't important to them but the personality is. Thanks to Ataru's words, Ruriri is survived and have a few followers re-follow her. After Ruriri thanks Ataru, he meet Koyori Kanda who have a similar appearance to his sister, Yuri. After Ataru discovered how to surpasses the game, he tells Marble paused the game a little and tells the other players the way to surpass it. After the discussion, everyone except one man was all surpassed the game. Marble wonder what was Ataru does, he revealed that he was cheating and Marble was surprised. Marble wants to glad that Ataru can used the cheating plan, but he said that other than cheating there's one more way to surpass the game. After Ataru learns an another way to surpass, he was regret and said that man can surpass the game too. When Marble said Ataru is not a hero, Koyori comes to protect Ataru and tells Marble that Ataru is already a hero to her.
During the RT Game, Ataru is thinking which tweet she should to post in public, soon she saw Nanami Misakura posted a tweet that she will stripping her clothes if her RT points reach to 1000. Ataru was surprised at how Nanami's tweet is (And also surprised at how nice her body is), he also wants to do the same thing but soon he realized no one will gonna see his body. After a few minutes of thinking, Ataru finally decided what tweet he should written and post it, though it's ended up only having 3 RT points.
After RT Game, Ataru called Yuri to asking if she is alright or not, soon Ataru give Koyori his smartphone and let both her and Yuri talking together. Then, Marble announced they will live in Real Account Resort for taking rest in one day.Both Ataru and Koyori enjoying their resting time in Real Account Resort. Later, along with Ataru and Ruriri Ichijou was "assigned" to a group. During the Dark History Trials game, Ataru's dark secret that he "killed" someone was revealed by Aiji Hoshina. Ataru tells everyone stop it and heard about his past, and revealed that Ataru's true name is Yuuma Kashiwagi. After everyone listening Ataru's dark past, Aiji noticed Ataru don't wanted his sister to be sad is just a lying. After Yuri re-follow Ataru once again, Aiji is disappointed at Ataru didn't suicide for Yuri unfollow him. Aiji continue to challenging Ataru and his friends in the whole game afterward. After Ruriri's death, Ataru's want to take revenge for her so Aiji requested Marble to continue the game and both Ataru and Marble accept it. During the game, Aiji keep said Ataru is a useless coward but because of this, Ataru able to founded out his hidden tweet and lose to Ataru. Aiji thought he is about to die but he didn't due to Ataru didn't actually hit the gong. Aiji said Ataru is a coward because he didn't kill him but Ataru replies that he will try his best to not kill anyone. After Dark History Trails finished, when Ataru is in troubled Koyori kiss his face, Koyori herself have no idea why is she kissing Ataru and tells him to forgot it.
Soon, both Ataru and Koyori back to the Real Account Resort and they saw there's survive ranking showed in the TV. When the ranking revealed Nanami's name, Ataru glad that she is survived. When the 4th ranking place was revealed, Koyori said that's Ataru but he deny it and said that's his twin brother, the real "Ataru Kashiwagi" (While the name is written Yuuma Mukai). Ataru is surprised at "Ataru" being showed up and said why is he still alive.
Chapter 11-70 (Second Season)Edit
Ataru appeared at Chapter 49, he returned to his original home and meet Yuuma. Ataru said he is happy that he is able to see his brother once again and taking his gun to shooting him. Ataru tells Yuuma don't run away and said he is not allowed to live in this world. Ataru keep saying that Yuuma must be died and said Ataru has make a promise with Koyori. After Ataru stabbed Yuuma's nose a bit, Yuuma asking him why is he stopped attacking and he doesn't understand what Ataru was saying at all, Yuuma said that Ataru was a coward and can't kill people. The fight between Ataru and Yuuma keep continuing until Masahide and Marble showed to stopping them, Ataru stopped his attack and back to the Real Account company with them.
Ataru returns once again at Chapter 68, to shows celebrating their victory and the end of the SNS Hide-and-Seek. Sayaka Shiiba replies that Yuuma's group is arrived as she expected, while Ataru keep being silent.
Chapter 71- (Third Season)Edit
Ataru appeared at Chapter 149, when Sayaka is about to said his reason on killing Yuuma, Ataru showed up and replies let him telling the truth will be better. Ataru replies he will tells the truth to Yuuma, and he also come to gives warning to every players that Yuuma will kills all of them someday later. This caused Yuuma was so angry and said Ataru is the one who coming to kill him, Yuuma replies he still remembers what was happened during they meet at their original home in half years ago and the wound on his nose is still around.When Ataru is talking, Sayaka comes in front of him and replies she wanted to see him so much, Aiji come along and giving Ataru a kiss. Ataru was surprised at Aiji's kiss and asking what's he doing, Sayaka was jealous at Aiji and also wanted to gives Ataru a kiss too, though Ataru tell them stop fooling around. Ataru revealed that Sayaka and Aiji was his partner in half years ago, and revealed there's one of partner works together with him, Koyori. Ataru mentioned at how Koyori's personality is, she keep the same personality up until during sometimes later her personality was suddenly changed. Ataru replies that both Koyori and Yuuma suffered an same "symptom". Ataru said that even though Koyori's personality was changed, he , Sayaka and Aiji still works together with her, until when Koyori's "symptom" has reached to the third stage. Ataru replies that Koyori's third stage of "symptom" is so scary, death isn't meant much to her and he referred her as a "cruel person". Ayame Kamijou wonder what's happened to Koyori and Ataru replies that he killed her, because she will keep destroying the things he loves. Ataru said he make a promise with Koyori that he will kill anyone who have suffered the same symptom as her. Yuuma said that he will never become like her, but Ataru disagreed with it and said he must be become like Koyori soon, due to both Yuuma and Koyori have shared similar "thing". Then, Ataru revealed an "present" to Yuuma which is Nanako Yuzuhara's head in front of him (Though it's not actual Nanako's head). Yuuma was gone into third stage of his "symptom" and tried to attack Ataru but it's stopped by Marble's subordinate. After Yuuma returns to normal again, Ataru wears Marble's mask and said he will waiting for him at the tower top. Ataru replies they will ends he and Yuuma's fight at the tower top, and also replies that Yuuma may be the only one who will survived at the tower top.
During the Anonymous Classroom game, Ataru is watching the players (Especially Yuuma) in a TV screen along with Marble. After Yuuma returned to his second stage of "symptom" state, Ataru can't believe this and state it's impossible to be returns to the previous state since Koyori never had changes back her original personality. Marble stated that the reason why Yuuma is able to return to "normal" is because of Ayame's love on him but Ataru disagree and being angry at him due to this will meant everything he did to Koyori is completely pointless. Later during Yuuma and his friends was celebrating his birthday, along with Marble was watching them in a TV screen. Marble wonder who will gonna handling the next trial since all other Marbles was defeated, Ataru respond that he will handle the next trial, as the final battle between him and Yuuma is finally begin.
- Ataru doesn't want anyone to know that he and Yuri are poor; as a result, he's rather stingy.
- Ataru believed himself killed his brother, though it's revealed in later chapters that it's actually Masahide and Marble who killed his brother.
- Though Yuuma is still alive thanks to their parents to using the CAP Technology.
- Ataru make a promise that he don't want to not killing anyone, though he broke his promise later as he killed Koyori by his own hand.