Karyuudo Tsukishima

Karyuudo Tsukishima (月島 狩人, Tsukishima Karyūdo) is the Tenth diary owner. A lover of dogs, Tsukishima runs a kennel home and breeds dogs, however, he has also trained them to attack and kill people. His diary is the "Breeder Diary". He is the father of Hinata Hino.

Personality
Tsukishima is a wealthy gentleman who runs Sakurami City's dog home, treating each of his dogs like a beloved family member. He is shown preparing for them expensive meals including wine, and even has them sitting at a long dining table, although it appears they are not trained in table manners. Tsukishima appears to care little for humans, including himself, eating noodle meals. Because of his detached attitude, Tsukishima has isolated himself from his family. He is shown to have a wife, but where she is during the events of the manga is unknown. His daughter Hinata loves him and wishes to earn his attention and love, having often been neglected by Tsukishima, even as a young child. Tsukishima is well aware of Hinata's need for approval, considering her to be very naive and "easier to fool than a dog".

His indifference to his daughter is shown very strongly throughout the series. Instead of fighting in the free for all himself he gives his diary to his daughter and forces her to compete on his behalf. Putting her in mortally dangerous situations while he hide in the safety of the mansion protected by his dogs monitoring the events on his super computer. He even goes as far as to force her to become a serial killer using the power he gave her to kill innocent people in an attempt to flush out another diary holder (though he promises her that if he becomes a god he go would back and change time) all so he could be come a god. This also shows a greedy and selfish as well has extremely manipulative and cowardly side.

He is very good at maintaining his daughter, as he convinced her to do many things that she would normally never do, such as killing people, lying and was presumably going to make her betray her friends. All by promising her if she could win the Survival Game for him, he would go back in time and undo her neglected childhood, though he later admitted this was just a lie, and even insulting her for believing he'd even want to redo things with his family. Though he did enjoy the company, and loved his dogs, he was still willing to turn them into killing machines, and sacrificed them when the free for all happened, showing he loved himself more.

Despite his icy exterior, Tsukishima appears to show some remorse for not being a proper father to Hinata, asking her not to become a bad person like he did.

Diary & Abilities
His diary is The Breeder Diary, which is mostly used by his daughter Hinata. Despite of this it's uses are clear, which involves to predict the movements of his dogs and those of his targets. With his Diary, Karyuudo can not only see the future of his dogs and also the targets they see but also control him to control his dogs and make them obey his every command, using codenames, like: Alpha 1 for a set of dogs, Alpha 2 for another set of dogs, and so forth. While this Diary grants him a powerful army of dogs, the weakness is that the more dogs he controls; the more difficult it is to keep track of their every movement and thus he can be rendered vulnerable. Though he appears to have been able to monitor the dogs through his huge super computer, minimizing this risk considerably.

As a diary owner, Tsukishima trained his dogs to be murderous and vicious attack dogs, giving them metal mouthpieces to enhance their bite's and physical attacks. He also owns a large computer mainframe which he uses during his planned attack against Yukiteru Amano and his friends. Which reveals both his technological expertise and the mastery he has over his dogs.

The Tenth's Trap
Karyuudo Tsukishima debuts with the other diary owners at Deus Ex Machina's first meeting of the survival game. Like the others, he decides to make the First owner, Yukiteru Amano, his target. By late May and early June, four diary owners had been killed, leaving Tsukishima quite fearful for his life. He begins to notice Aru Akise lurking about outside and informs Hinata of his presence, guessing he is a fellow diary owner. Tsukishima comes up with an idea to give Hinata power over his diary in order to expose Akise as a diary owner, as well as make his move against Yuki. During the second meeting with Deus, Tsukishima requested to give his diary to a third party, much to Deus' surprise. Keigo Kurusu, the Fourth diary owner, informs Yukiteru of this event, revealing Deus believed it was at first an excuse to get out of the game but then allowed Tsukishima's request. Tsukishima loans Hinata his diary and his attack dogs, promising Hinata that if he became God, he would go back in time and make up for neglecting her.

Having trained his dogs to attack people, Tsukishima stages a number of serial killer-like murders, creating a similar public scare like that of the Third diary owner Takao Hiyama. The dogs work on their victims was at best horrible, acting devouring parts of their victims' bodies and leaving the remains for the police to find. When Yuki starts his new term at Umesato Elementary School, Tsukishima had lent his diary to Hinata, giving her the opportunity to gain his love and approval. Upon meeting Yuki, Hinata suggests investigating the sites where her father's dogs killed people. Yuki agrees, accompanying Hinata, Mao Nonosaka, Ouji Kosaka and the Second owner Yuno Gasai to the park where they find one of the crime scenes. Hinata runs off ahead and fakes her death, using a fake arm to make it look like she has been torn apart by her attack dogs, on loan from her father.

Akise arrives, escorting Yuki, Yuno, Mao and Kosaka to a nearby building where they manage to fend off the dogs following the instructions on Yuki's diary. Afterwards, Mao reveals herself to be in league with Hinata, taking Yuki at knifepoint. Hinata enters and takes Yuki's phone, accusing Akise of being a diary owner himself. However, Akise uses a coin toss game to outwit Hinata who tries to use Yuki's diary to predict the outcome of each coin toss. However, Akise deceives Hinata and she is forced to surrender Yuki. Akise fools Yuki into believing he has a Future Diary in order to ensure victory, but Yuno attacks him and reveals the truth. Nevertheless, Akise performs a final coin toss after conspiring with Yuno to again fool her by tricking Yuki into believing he failed at the coin toss.

Yuno attacks Hinata to get Yuki's diary back, but Mao takes a blow for Hinata and is stabbed. Yuki, Yuno, Akise and Kosaka take the opportunity to flee. The enraged Hinata orders all of the dogs to chase them, and the goes outside with the wounded Mao where she regrets her actions, believing Tsukishima will never approve of her. Yuki returns with the intention to save Hinata after she promised that they could all leave as friends if she failed the coin toss game. Yuno charges in first, taking Hinata at knifepoint and threatening to kill her unless she surrender the Breeder Diary. Yuki manages to calm Yuno down by declaring to his friends that she is his girlfriend, allowing Hinata to be spared.

Hinata laments for failing her father, only for Tsukishima to speak up through a radio device on a dog, who had actually been listening in the whole time. Tsukishima apologises to Hinata for mistaking Akise for a diary owner, but reveals his role in the game is over. Hinata asks about his promise, but Tsukishima apologises again and reveals it was a lie; in the anime, he openly laughs at Hinata's naivety and his own promise. Tsukishima criticises Hinata for her naivety, but tells her not to become a bad person like he became. Clutching a family photo of himself, his wife and a young Hinata, Tsukishima informs Yuki to beware of the diary owners who act nice, but can also be deceptive.

Kurusu suddenly appears behind him, having tracked him down using his own diary. Tsukishima identifies Kurusu as one of the "nice people", and is shot in the back of the head by Kurusu, his death heard by Yuki and Hinata. Kurusu frames Yuki and Yuno for killing Tsukishima, to cover up his own actions in his plan to become God to save his terminally ill son. However, Masumi Nishijima eventually clears Yuki and Yuno of the charges when Minene Uryu reveals Kurusu's alliance with her.

The Final Battle
Tsukishima appears in the third parallel world created when Yuno, Muru Muru, Yuki and Minene performed a time leap two years into the past. When Tsukishima's dogs are disturbed by the explosions occurring at Sakurami Elementary School caused by the four time-travellers, he heads outside to check on his pets. However, he is surprised to find Hinata calming down the dogs. Hinata admits she has gained an attachment to the dogs, leading to a better relationship between Tsukishima and Hinata, altering their future.

In the last chapter, Tsukishima, his wife, and Hinata are seen among the supporting characters on the streets of Sakurami City, living a better life together. In the anime, Tsukishima becomes a better parent, allowing Ouji Kosaka and Aru Akise to play with his dogs. He is last seen taking Hinata, Mao, Kousaka and Akise out.

Trivia

 * Karyuudo is not actually named until after he is killed by Kurusu.
 * He and Minene Uryu are the only diary holders who were not killed by Yukiteru or Yuno.
 * His name is a nod to the Roman moon goddess Diana, his name containing the kanji for "moon" (月) and "hunting" (狩). Karyuudo has trained his dogs to hunt down opponents, just as Diana was a great hunter and used animals to hunt as well.
 * In the manga, Karyuudo's dogs wear large metal mouthpieces whilst in the anime, their teeth are shown to be wearing metal, serrated braces-like devices.
 * While speaking in standard Japanese most of the time, Karyuudo has been shown to occasionally slip into a Kansai dialect. For example, he uses おおきに (romanized as ooki ni) in the first episode, which is the Kansai equivalent to ありがとう (arigatou) in standard Japanese. He also slips into Kansai in his last conversation with his daughter before he is killed by Kurusu.
 * He and his daughter (Hinata) have different surnames; it is possible that Hinata took her mother's maiden name.
 * In ending one of the show where all the Diary owners are seen standing next to each other in order of their numbers, Karyuudo is shown standing left of Minene, despite him being Tenth and her being Ninth.