Mizuki Kurashina
Kanji 蔵科 ミズキ
Rōmaji Kurashina Mizuki
Alternate Names

Personal Info
Gender Male
Birthday April 19
Age Unknown
Status Alive
Family Ritsuko Kurashina (mother)
Professional Status
Occupation Founder and Administrator of "Black Aquarium" (Second Season)
First Apperance Chapter 14

"The connections made on social can be as strong as those of blood."
– Mizuki Kurashina, Chapter 53

Mizuki Kurashina (蔵科 ミズキ, Kurashina Mizuki) is one of the antagonist in the first half of second part of the story, one of male protagonist in second half of the second part and third part of the story. He become Yuuma Mukai's friends and followers in the later story.



Mizuki has a very deranged personality, and is also an admin of a suicide website, Black Aquarium. Murder and death is not something that he fears.


Early StoryEdit


Young Mizuki want to die with his mother

Mizuki is live with his mother, Ritsuko Kurashina during his childhood. One day, Mizuki saw his mother suicide in her room and saw the storybook named Country of Despair. Mizuki believed his mother didn't dead yet but her soul is living at Country of Despair and for Mizuki comes with her, he thinking of wanting suicide so he can go to the Country of Despair with his mother, but as soon he realized that he didn't have any despair yet. As such, Mizuki started to taking a lot of despair photos as his "tickets" so he can able to go to the Country of Despair. Mizuki's mother death face was his very first photo of his Despair collection.

Chapter 11-70 (Second Season)Edit

Mizuki first appeared in Chapter 14, during the Rear Live Game he joined with another player, which showed he trying to kill that player to see how special his show are about, in which scared Yuuma Mukai for this show. Later, during the Read-though Extermination Campaign game he comes to see Yuuma, greeting him and asking him if he like to eat the raw meats but Yuuma said nope, then he leave the slot-machine area and said Yuuma and he are "same genre".

Mizuki kills the players as they requested

A day later, three players requested Mizuki to kill them so they can free from despair feeling, he accepted the request. Then Mizuki brought the three players to another place, which Yuuma happened to see them. When Chiho Fujimaki is nearly kill by Mizuki, he is stopped by Yuuma. When Chiho is started crying, Mizuki think her crying face are good so he take the photo and put into his despair collection. After Yuuma describe Mizuki is crazy, he stopped Yuuma from replying the message, it makes Yuuma so scared because he will gonna die soon because of it. Suddenly, Mizuki stopped his action and let Yuuma to be alive and said he is not the "best prey". Mizuki gives Yuuma's crying photo back to him as the photo is too lame and not good in his despair collection.

Mizuki taking photos

During Yuuma finally get the No. 45 stamp and being use it, Mizuki steals Yumma's No. 45 stamp and he deleted it. Yuuma asked him why Mizuki did this, he replies in this way the players will feel even more despair and become part of his despair collection. Mizuki is also interested to see how Yuuma's face look like when he feel despair, however Yuuma still being claim which make him wonder why is he still haven't feel despair yet, he said it's impossible to change the situation. After Yuuma ended the game with killing Marble, Mizuki realized that Yuuma is the "best prey" that he wants for a long time, he swear that he must getting Yuuma's despair photo and kill him.


Mizuki taking Yuuma's phone

A days later, the Big Flame Festival game are begin and Mizuki is in the same group as Yuuma and his friends. During the phones are exchanged, Mizuki's phone are in Kirika Sakuragawa's hand and he replies that Kirika is free to see his phone, but Kirika is scared to seeing his phone. When the phones are exchanged for a second time, both Mizuki and Yuuma's phone are exchanged and Mizuki said that they will seeing both of their's phone together. Mizuki reveals Yuuma's first memories and the fact that he has amnesia. Mizuki also taunts Yuuma by reading the said person's diary entries, exposing Yuuma's misanthropic views, and the fact that he finds the world boring. Yuuma reacts quite violently to that, making a move to snatch his phone back. Mizuki sends Yuuma to the edge as he delivers the final blow, which is the voice recordings of every single grateful message sent to Yuuma, claiming that, "he must've listened to it every night". Yuuma suddenly screams in pain and his scar bleeds out.

When Yuuma finally showed his "true" color, Mizuki said he is glad to see his "true" color and replies he likes current Yuuma a lot more than before. Mizuki let Yuuma to see his phone and said his phone didn't have anything to see. Soon, Mizuki's phone is ringed and it's showed "Country of Despair" calling him, hearing a women's voice which make him through it's his mother who calling him. Then, Mizuki realized that isn't his mother but a apps that use to answering user's question and he is fooled by Yuuma. Mizuki replies he changed his opinion said that instead of like, he hate the current Yuuma a lot more than before.

Mizuki cries after his despair collection was deleted

Then, Yuuma explained the actual plot of the Country of Despair, which Yuuma shows that the book has empty pages intended to allow the reader to see through the last two pages together. This causes the two pages to overlay on each other, presenting a different ending. This overlay turns the noose that originally hung from the ceiling into a sword being pointed at God. "God's invitation was for the country of despair. Pietro's unhappiness was the author's own". At the bottom of the overlayed pages is a bar code which was a message to the reader not to die, changing the story from one of despair, to one of hope. Suddenly, Mizuki went crazy as he can't believe this is the actual story of Country of Despair and he tried to prove this by his own, realized Yuuma didn't said anything wrong and said he will never meet his mother again. Then, Yuuma deleted all of Mizuki's despair collection included his very first photo which is his mother's death face, he is sad and started to cry due to he can't see his mother anymore. When Mizuki is crying, Yuuma came in front of him and telling him don't act like a crybaby or he will die here, though it's soon stated by Yuuma that he don't have any useful anymore.


Yuuma and Mizuki works together for the first time

During the SNS Tag Game, Mizuki joined with Yuuma to fight against the hunters, soon he replies Yuuma has changed his life since the Big Flame Festival so he will be forever follow with Yuuma and works together. Yuuma disagree and tells Mizuki get out but he didn't listen. Later, Mizuki become Yuuma's follower and used bracelets to locked Yuuma's right hand so he won't leave him. When the DQN Marble founded Mizuki and Yuuma, he saved Yuuma's life by protect him with his body but he is heavily injured. Mizuki request Yuuma to bring him into the hospital to heals the scar, Yuuma originally don't want to do it but due to the bracelets on his hand he is forced to do so. Later, Yuuma succeed to bring Mizuki into hospital and heals by Tamae Hanaden, who is Mizuki's follower. After Mizuki finished the mission that have to scan his follower's "Marble's mark", he stated that Yuuma is still not save yet due to Ayame Kamijou are still his follower and haven't finish the mission yet, Yuuma soon realized Mizuki want him to dismiss her so both him and Mizuki's life won't be in danger, but Yuuma didn't and saved her from her brother, Shoujo Kamijou.


Mizuki state the connection on social as strong as those of blood

After Ayame is saved, he ask her if she want to eat raw meats or not, but she said didn't want to eat, though he said even if she want it he won't gives her the raw meats. Later, when Mizuki and his group were attack by the hunters and DQN Marble, both he and Ayame tried to make Yuuma claim down and Mizuki replies that he is very surprised the connection between SNS (Mizuki, Yuuma and Ayame) are way stronger than connection of their actual family members does. Then, Yuuma drive the car and tells Mizuki and Ayame die together with him and Mizuki have no problem with it. When another new mission was announced, along with Yuuma and Ayame has gone to see Mitsuru Kariya to reunion the follower once again, and they completed with the reunion except of Yuuma due to Mitsuru hate him so much.

Mizuki and Yuuma fight against DQN Marble

After Kirika's name is listed in the death list, along with Yuuma they went to "kill" the DQN Marbles. Both Mizuki and Yuuma tried a few times to "kill" DQN Marbles, while being failed they find out the solution of how DQN Marble did know which is players. After Yuuma learned Kirika's last sentence meaning, he and Mizuki tried to changed their GPS position from Japan to Hawaii and it did work. Thought when the last DQN Marble is about to went falling down from the Tokyo Tower, Yuuma and Mizuki set their GPS back to normal and do revenge for the players who died at DQN Marbles' hand, they defeated DQN Marble and Mizuki saved Yuuma from from fall down with DQN Marble.

Mizuki prepared to die with Yuuma

Later, along with Yuuma, Ayame and Chiho was gone to the Real Account company, in order to obtain the "Player Revive" technology to destroy the Real Account. After Yuuma founded Nanako Yuzuhara's collapse, Mizuki tells Yuuma that she is dead but Yuuma can't believe it and punching him. Shortly after this, Nanako calls Yuuma in the phone and replies she is in Real Account world now. When Yuuma arrive at the big gate, Marble announced an another new mission of having every players returns to the place where they started the death games. Because of lack of times and finding the technology, Yuuma decided to asking everyone for who will gonna stay with him, Mizuki answering yes and said he will be happy to see Yuuma's death face and he will die together with him. Mizuki and other has try their best to thinking the password of the big gate, until Yuuma finally figured out the password and the actual place of where the start point the mission meant.

Mizuki realized how dumb he didn't notice it's take place in real world

After revealed the death games is taking place in real world, Mizuki replies why is he so dumb to not realize about this until now when there's so many things can proved they're not in the internet world but in real world (Wounds, bloods, feeling). While Yuuma is finding Nanako, Mizuki found up a small entrance, enter it and saw Marble and other players were here to celebrating the end of SNS Tag Game.

After SNS Tag Game is finally ended, Mizuki go out with Marble and the other players, they have surprised at the players who originally will die at stadium are all returned to the Real Account area thanks to Yuuma using CAP Technology. Soon after Marble were punched by Yuuma, he decided to destroys the Real Account company due to not able to continue the death games anymore, Mizuki saved Yuuma from nearly hit by the rocks from ceiling.

Along with Yuuma and the other players, Mizuki is survived from the company crushed.

Chapter 71- (Third Season)Edit


Mizuki agreed with Yuuma's answer

Sometimes after the event of Second Season, Mizuki closed his suicide website along with Real Account official page. During August 27, Yuuma calls Mizuki to joins Ayame's birthday party at beach. When the group comes into the beach, Mizuki is being sad and have no energy due to he afraid of waters and the sun. Yuuma push him into the water and tells him don't be stubborn. Mizuki is sad again due to the raw meats being cocked, and ask Yuuma if he can live like a normal people or not. Yuuma answered it Mizuki can as long as he really want to do so, he suddenly agreed with Yuuma. After returning home, Mizuki started to draw a lot of storybooks and done a lot of artworks in the whole night, but he soon forgot about this.

Half years after the event of Second Season, Marble is returned as "True Marble", he chosen 30 players to join the Real Account Tower and play the death games once again, Mizuki is one of the 30 players choose by Marble.


Mizuki and Kotoko killing each other

During the first game started, Mizuki is finding his way go to the goal and suddenly meet Kotoko Tobu, who is known as a serial killer. Mizuki state he know about Kotoko due to one of his customer at suicide website mentioned his family were killed by her, they starts fighting each other. When Kotoko ask why is Mizuki like Yuuma so much, he respond is because Yuuma has changed his life from killing for the despair to killing for Yuuma, he also stated he is lived for Yuuma and he can do anything for him, even if Yuuma wants to kill god. Soon, Mizuki saw Yuuma was beaten by Magura Aizawa which is surprised him a bit.

After the first game finished, Yuuma noticed Mizuki has showing weird expression lately. Yuuma wonder what's wrong with Mizuki, Mizuki only respond he will kill Yuuma one day. Mizuki's wish that want to achieve by Marble is "Kill Yuuma with cutting every part of his body to none".

During the ID Gather Game, Mizuki is tag-team with Hako and Yui Akesatoya. When Hako tells Mizuki can join into his new world, he replies that Yuuma is not chosen and he will die soon, which makes Mizuki angry and tells him don't disrespect Yuuma or he will be killed. Then, Hako tell Mizuki to see what's Yuuma doing now and he seeing Yuuma showed to be friendly and playing with OL Marble.

Mizuki joined Hako's new world and wants to kill Yuuma

Mizuki was disappoint at Yuuma and start crying, he stated he will joined Hako's new world and wants to kill Yuuma. Soon, Mizuki works with Hako to play the game, and they finished the game. Mizuki is watching over Yuuma and hope he don't die here, as Mizuki will be the one who gonna kill him.

Mizuki wants to challange Yuuma

After the second game is finished, Mizuki comes into Yuuma's room and tried to kill him, he said he is disappoint at Yuuma and he is no longer the Yuuma who is strong, scary and never scare at anythings that he know, Mizuki leaves and tells him that he will kill him someday. As the third game started, Mizuki is works together with Hako once again, Mizuki is slowly started being brainwashing by Hako. Later, when Yuuma meet Mizuki it's showed that he is abused by Hako and he said he like it. Then, Yuuma break his own finger to shows how he want to reunion with Mizuki, he tells him they will having a match to fighting each other at 9:00 p.m and Mizuki agreed.

Mizuki fight against Yuuma once again

When Yuuma and Ayame arrived, the match is started. In the whole fight, it's revealed all Mizuki want is a dominator who can gives him a lot of despair but all of this were destroyed by Yuuma during the Big Flame Festival game. Yuuma, then replies Mizuki also did the same thing to Yuuma too and that's what caused Yuuma changed his personality completely, even so he still hopes they can reunion once again because they are friend. Shortly after that, Mizuki defeated Yuuma but Yuuma still catching the iron chain on his right hand, which is the bracelets he wears together with Yuuma during the SNS Tag Game. Ayame summons Electric Girl shocks Yuuma to awake him. When Yuuma is awake, he shows Mizuki's drawing picture to him in his phone, which is said to be draw by Mizuki himself. One of the storybook Mizuki written, "Thieves and the Juvenile Miyu", is showed the concepts of the storybook is based on the events happened to him in half years ago, the thieves are even based on both Yuuma and Ayame.

Mizuki reunion with Yuuma and Ayame

Yuuma stated all Mizuki actually want is not a dominator, but a real best friend that understanding each other. When Mizuki realized what he wants, his head is started hurting and Hako tried to brainwashing him again but it's stopped by Yuuma. Suddenly, Mizuki noticed how scary Yuuma was during he attack Hako, Mizuki realized Yuuma didn't become weak but become even stronger than before, it's just he can't see it. Yuuma requests Mizuki to joins with him and Ayame repeat to said the line Mizuki said once before, then Mizuki agreed and the former "SNS Tag Game-Yuuma Team" were reunion once again. Shortly afterward, Hako used one of his pocket monster's ability to steals every pocket monsters that Mizuki owns, so his pocket monsters collection are all empty.

Soon, they found the hotel and resting at there. Yuuma is thinking how to re-catch every pocket monsters to Mizuki. Mizuki respond he don't care and he said he can die here but Yuuma don't allow it. Then, Mizuki think of apologize to Ayame due to what he did to her during the fight against Yuuma, but he don't know what should he do and think giving a ton of raw meats to her are the only way he can think. Mizuki fall asleep after the apologize, and his face look a bit better than usual after awake. Yuuma said he figured how to help Mizuki to re-catch every pocket monsters before the deadline, but Mizuki disagree as Yuuma and Ayame still haven't catch all 50 pocket monsters and this plan is too dangerous. Then, Yuuma summoned one of his monster and used it's ability to guess if this plan will gonna works or not, however it's not. Even so, Yuuma still try to do so and Mizuki have no choice but agreed with him.

During the plan, Mizuki hidden himself and using the iron chain that Hako gives him as a trap, in order to make Planning Department Chief Marble fell into the trap, shortly they successes to steals all of Dr. Marble's pocket monster. Soon, all of pocket monster Yuuma steals are all returned to Dr. Marble by using his stealing monster's ability. Yuuma thought it's failed and will lose, but suddenly Yuuma obtained a No. 101 Pocket Monster, King Swagger Mouse by fused all of Swagger Mouses into one. With the helps of Karua Sakura and her followers, the King Swagger Mouse's power has reached 5369% energy and they successful defeated Dr. Marble.

After Real Account Go is ended, along with Yuuma and the others are making a funeral for the players die in this game, but soon Airi Homura destroys the funeral by burns the area. During the night, Mizuki is watching over Yuuma's room to make sure no one gonna attack him. Kotoko shows up and went to kill Yuuma due to he killed Dr. Marble, but it's stopped by Mizuki. On the second day, the fourth game is started, following Public Relations Officer Marble's order Mizuki have to tagged with Kotoko. Mizuki is not happy to working together with Kotoko, which causing he want to fight against her every times. As the time progress and fight goes, Mizuki is slowly started to know about Kotoko's back story and wonder what is she actually wants, thus is slowly making Mizuki started want to protect her. After being attacked by the Unscrupulous Hunter Marbles numerous times, both Mizuki and Kotoko can't holds on anymore and they believed they will die soon.

Mizuki defeats Kotoko

Even so, Kotoko still want fight Mizuki for one last time, and she finally falling down. Shortly after Kotoko's defeats, the Unscrupulous Hunter Marbles suddenly came to giving her a punishment but Mizuki defend her. When Kotoko is nearly dead, her eyes can't see things properly and she thought Mizuki as her long death son, she replies she is feel so sorry to him due to she never care about her son even when he is killed by a serial killer, Kotoko said all she feel during when she killed person for a first time is not revenge but instead it's make her interests at killing. Then, Mizuki is realized all Kotoko actually want is not killing but finding someone to gives her a punishment.

Mizuki accepted Kotoko's last request

Kotoko requests her "son" (Mizuki) to kill her, Mizuki accepted and said good night to her for die peaceful. After Mizuki killed Kotoko, Yuuma comes to comfort him, but the alarm is ringing and the Unscrupulous Hunter Marbles appears to giving Mizuki a punishment for doing such a unscrupulous behavior. Yuuma and Airi brought Mizuki run to hidden themselves.


  • Superhuman Speed - Mizuki can did a very fast moves with his attacks.



  • Mizuki haven't sleep for a several years. Thought it's started getting heal in the later story.
  • Mizuki only like to eat a raw meats, when he eats a cooked meat he want to vomit.
  • It's showed that Mizuki really like Yuuma, he even prepared to die for him.
  • Mizuki's wish that want to achieve by Marble is "Kill Yuuma with cutting every part of his body to none".