Friends Masumi Nishijima : is the chief investigator and Keigo's subordinate within the police. He is an ally of Yuki within the police force. In
Mirai Nikki: Mosaic, Masumi is interested in Minene, when the latter disguised herself as a police detective she killed. Even when he learns her real identity as a terrorist, Masumi still continues pursuing a relationship with Minene, much to the latter's confusion. After the incident where Keigo commits suicide, he entrusts Masumi his role of balancing out the other Diary users. Masumi was killed by the Eleventh's men by using himself as a shield of gun shots to protect Minene. In the Third World, Masumi and the Second World Minene is shown to be living happily with their children.
Ouji Kosaka : is a classmate of Yuki's who used to bully him in the past but later became his friend during the Diary Game. He receives his "Kosaka King Diary" from the Eighth Diary user. This diary records any "triumphs" that Kosaka achieves in the future. Its usefulness is limited, however, as Kosaka views everything he does correctly as a great personal triumph, regardless of how small the task. Another serious shortcoming of his diary is that it only records when Kosaka will succeed, and therefore will not update if he is going to fail. He revealed the reason he bullies Yuki is because his 'crybaby face' reminds him of a stupid dog of his. Yuki gets mad and kills him with a pistol. In the Third World, he is seen with Karyuudo, Hinata and Mao.
Hinata Hino : is one of Yuki's new friends in his new school. Her father is actually Karyuudo Tsukishima, the Tenth Diary user. Although she initially attempted to kill Aru she did so under her father's promise (later revealed to be a lie) that they could be a family again. After her father's death, she helps Yuki whenever possible. She receives her "Friendship Diary" that predicts her friends' actions, from Eighth Diary user. In the Second World, she is killed by Yuki after a failed attempt to convince Yuki the fact that the resurrection of his parents would be impossible even if he were to become god. In the Third World, she is seen with her father and friends.
Mao Nonosaka : is one of Yuki's new friends in his new school. She is a quiet, polite girl who is constantly photographing the things around her, though her photos mainly center on Hinata. She is in love with Hinata and would do anything for her. She received her "Hinata Love-Love Diary", which allows her to predict Hinata's future similarly to the way Yuno predicts Yuki's, from the Eighth Diary user. In the Second World, she is killed by Yuki after calling him a coward. In the Third World, she is seen with Aru, Kosaka and Hinata.
Amano family Rea Amano : is Yuki's mother who is rarely at home because of her work as a video game programmer. Despite this, she has a very casual and close relationship with her son and even approved Yuno as his girlfriend. However, Rea is oblivious of her son's involvement in the Diary Game and Yuno's true nature. Prior to the series, she divorced her husband, Kurou, for gaining a large debt. She later confronts her ex-husband and is killed by him, unintentionally, when he stabs her for dragging him back to the Sakurami Tower. In the alternative universe, she is seen alive along with her husband, Third World Yuki, and Yuki's new girlfriend Moe Wakaba. She is named after
Rhea, the mother of
Jupiter's Greek equivalent,
Zeus.
Kurou Amano : is Yuki's father, who is divorced from his wife for gaining a large debt. He appears later trying to reconcile with Yuki and their family. However, this is a facade as Kurou is secretly working under John Bacchus to destroy Yuki's diary without knowing it will kill Yuki, in exchange of having his debts paid. But his plans are foiled by Marco and Ai, forcing him to escape only to encounter his ex-wife whom he accidentally kills. Kurou starts to feel guilt and a desire to make up to his son for what he has done. When he is at a shrine with his son, he is stabbed in the abdomen by Bacchus' men. He is named after
Cronus, the father of
Jupiter's Greek equivalent,
Zeus.
Gasai family Saika Gasai : is Yuno's adoptive mother. Though dead throughout the majority of the storyline, she is shown in the past to have abused and locked Yuno in a cage, and vents her frustrations on her, claiming she is a bad daughter. Saika's abuse of Yuno is apparently fueled by her own insecurities and self-hatred. In the alternative universe, when the First World Yuno tried to assassinate her Third World self, Saika defends her, and her viewpoint towards her daughter changes for the better.
Ushio Gasai : is Yuno's adoptive father. He is known to run the Sakurami City bank that Bacchus uses as a shelter during the invasion where Yuki and Yuno attempt to assassinate Bacchus to win the Survival Game. Unlike Saika, Ushio was never directly abusive towards Yuno, but he intentionally worked longer hours as a means of avoiding Saika due to her ever-increasing emotional instability. Because he was not around, Saika's abuse of Yuno continued unchecked. In the alternative universe, Ushio shown to be a much more caring man to his daughter.
Minor Orin Miyashiro : is a member of Tsubaki's cult and a personal friend of Ai. After the Omekata cult incident, she is seen as an assistant to Kamado. Her diary is the "Orphanage Diary", which predicts Kamado's orphans' actions. She speaks with a polite, yet sarcastic tone. Orin's head is sliced off by Yuno as part of the plan to kill off Kamado. In the Third World, she is seen with Tarou.
Tarou Nanba : , nicknamed , is one of the orphans Kamado took care of. He is very determined to make sure she succeeds in the survival game, feeling she is the only person who can make a better world for the orphans. His diary is the "Copy Diary" and can mirror the abilities of other diaries. He is very strict with Ai and Marco to the point that both dislike his attitude and think he is annoying. He is killed by Yuno, moments after realizing he was only used as a pawn. In the Third World, he is seen with Orin.
Funatsu : is the second-in-command of Tsubaki's cult. He is responsible for her parents' death as well as the constant raping she suffers at the hands of the cult members, not wanting the cult to disband, according to her parents' decision, and took over leadership. In the alternate universe, he is caught trying to insert a makeshift bomb within Tsubaki's parents' car, changing the future of the cult and Reisuke's family.
Ryuji Kurosaki : is the secretary of Sakurami City. His diary is the "
Secretary Diary", which records all of the Mayor's actions. He is killed by Bacchus for becoming a security risk when it is revealed that he will in the future be captured and give up the passwords for the vault in which they are taking shelter. In the anime, Ryuji is tortured and killed by Minene instead.
Moe Wakaba : is Yukiteru Amano and Yuno Gasai's classmate one year prior to the events of the series. Yukiteru had a crush on her but she turns him down after he gives her a love letter, much to Yuno's relief. Moe reappears in the Third World, after Yuno traps Yuki in an illusion world in which Yuno does not exist, and Yuki can have anything he wants, and Moe is the girl Yuki wants, but Yuki denies her (while, in the anime, she even undresses to seduce him). After the Survival Game concludes, the Moe of the Third World is in a romantic relationship with the Yukiteru of the Third World, as such both are seen holding hands and smiling at one another. ==References==