Mao Nonosaka

Mao Nonosaka (野々坂 まお, Nonosaka Mao) is one of Yukiteru Amano's friends at his new school. She owns the apprentice diary, "Hinata Love Diary".

Personality
Mao is a very gentle, polite and perky girl, using honorifics towards most people she knows. Her best friend is Hinata Hino, whom she loves deeply and is very protective of.

She is an open lesbian and clearly proud of her adoration of Hinata, willing to do anything for her. Hinata is well aware of Mao's affection, although she shows awkwardness when Mao expresses her more perverse adorations of her. Mao has a fascination with Hinata's breasts and expresses her desire to see them get bigger, much to Hinata's embarrassment. As a hobby, Mao often takes photographs, usually at inappropriate moments.

Mao is devoted to Hinata and willingly to do anything to protect her, even going along with her plan to attack Yuki, Yuno Gasai and Aru Akise for the sake of Hinata's relationship with her father Karyuudo Tsukishima. She is relatively harmless, but if anyone threatens Hinata, she will display a more dangerous side and is able to use a knife. She will also throw her life on the line to protect Hinata, even if it means being stabbed by Yuno. She holds Akise and Yuki in high regards, considering them good friends, and while she still sees Kosaka as a friend, she often teases him for his self-centered ways.

Appearance
Mao is a girl with long light purple hair, and aqua blue eyes. Her clothing style is a sailor dress-orange top white undershirt with a long brownish-red skirt and a pale pink beret.

Diary & Abilities
Mao's devotion to Hinata and her willingness to do anything for her is her strongest ability, being more than willing to protect and fight for Hinata. While she leaves the thinking to Akise and Hinata, Mao is willing to pitch in and help out her friends when needed, following Yuki's directions to fend off Karyuudo's attack dogs, and helps form a human stack to get Kosaka through a ventilation shaft during Yuki's kidnapping. She is also shown to have some skill with a knife.

Her Apprentice Diary is the Hinata Love Diary, which works similar to Yuno's diary by focusing entirely on Hinata's actions. However, it has a more sexual aspect to it, complimenting Hinata on her looks and breast size, and expressing Mao's own delight at seeing Hinata get surgery down to her cleavage. As an Apprentice Diary, it is reliant on a signal from Kamado Ueshita's Server Diary to function, but Mao will not die if it is destroyed.

As with Yuno and Yukiteru's diaries, Mao's Hinata Love Diary covers the main weakness of Hinata's Friend Diary, allowing them to form an effective team.

The Tenth's Trap
With Hinata, Mao introduces herself to Yukiteru. When Yukiteru accidentally pulls Hinata's pants down, she laughs along with the class and takes a picture. Later on, she is seen with Yukiteru, Hinata, Yuno, and Kosaka at the crime scene and park. When the group finds Hinata's supposed corpse, she seems extremely distraught. The group rushes to the observatory and follows Yukiteru's orders when he calls out his diary results.

After Yukiteru reveals his diary's true nature, she goes to hug him in gratitude, but quickly switches, putting a knife to his neck and holding him hostage against Yuno. When Hinata is revealed and in possession of a diary, she backs her up in her arguments against Aru. When Hinata follows through in Aru's coin toss game, Mao shows great disapproval of her choices. She releases Yukiteru, after Hinata loses, and pulls out a knife. Yuno, assuming she was going for Yukiteru, charges at Hinata. Mao jabs her knife into Hinata's hand and blocks Yuno's attack, allowing herself to get stabbed by Yuno. Mao passes out in Hinata's arms as the rest of the group exits the observatory.

Rescue Operation
To celebrate Mao's recovery, Akise Aru suggests that they go on a vacation as he had tickets provided by a friend. She is with Hinata in a bath and Hinata discovers that Mao was taking pictures of her underwater via cellphone. After having breakfast the next day Akise reveals that he is actually looking for Yuki and the four begin their search. Akise devises where Yuno may be holding Yuki and Hinata is contacted by the latter. Hinata goes to find him telling Mao to tell the others but Mao is unsure and her suspicions are confirmed when Akise warns that it could easily be a trap. They follow Hinata and find Yuki, but this was simply a trick and the trio are locked inside a room which is slowly filling with gas.

The Seventh's Battle of Love
Akise Aru devised a plan to hide Yuki from 8th's apprentice diary holders, they would hide him at Kosaka's mansion and then cut off the nearby signal tower in order to stop their diaries from functioning. Yuno Gasai, however, thwarts their plan to get Yuki's attention. Akise and Kosaka split up from the others and try to shut down the tower manually meanwhile the apprentice diary holders track Mao and the others. Mao and Hinata attempt to hold them off but are both injured by Ai's throwing knives. After Ai and Marco face Yuki and Yuno, Marco and Ai rescue Mao and Hinata shortly after setting the mansion on fire.

The Eleventh's Kingdom
Mao, Hinata and Kosaka meet Minene Uryu and Nishijima and explain that they have all become apprentice diary holders and that Akise told them to find them, to propose an alliance. Both Minene and Kosaka flatly refuse regardless they come to terms and meet up. Mao, Hinata and Kosaka specifically are used to distract Eleventh and enter fake log entries to confuse him. However, they are unaware of his secretary's diary which ultimately leads to their capture. The guards that captured them were unwilling or rather unsure whether or not to kill them until Kosaka mentions HOLON III, which prompts the guards to execute them. Both Mao and Hinata threaten Kosaka, but they are saved by Yuno Gasai. She later split up from the trio and they are not seen again until after Eleventh is thoroughly dealt with.

The End Begins
With the end of the Survival Game - and thus the universe - looming nearer, Mao and her friends were recruited by Aru Akise to help protect Kamado Ueshita from Yukiteru and Yuno. She observed Akise's confrontation with Deus, learning that he was an artificial being created specifically to monitor the Survival Game from the human world, and saw him narrowly escape deletion when Kamado gave him the Detective Diary with the power of her Server Diary. When Akise returned, he brought Mao and the others into his plan to stop Yukiteru and Yuno's rampage.

When the First and Second diary holders came searching for the Eighth, Akise engaged Yuno in battle to force Yukiteru to hunt Kamado alone. When he caught up with her, he was confronted by Mao, Kosaka, and Hinata, who called him on his actions and tried to convince him that his quest to become God was pointless - as Akise had learned, not even a god could resurrect the dead as they were in life. Yukiteru's resolve wavered, but Yuno's machinations led him to reject his friends' pleas, believing that they were trying to betray him. Consumed by panic and paranoia, he fatally shot Hinata, leaving Mao horrified and enraged. She moved to avenge her friend, only to become Yukiteru's next victim; Kosaka would soon follow after giving the First a final denouncement.

In the manga, Akise arrives in time to see Yukiteru murder Mao and Kosaka, but chooses not to intervene in order to preserve the future predicted by his Detective Diary. In the anime, Akise arrives after all three of Yukiteru's former friends are dead, expressing regret that they had to die in order to fulfill his predicted future.

Final Battle
Mao was reborn when Yuno, Yukiteru, Muru Muru, and Minene created a new world by leaping back in time. She is not present during the final battle, but she appears in the aftermath with Hinata, Kosaka and Akise. She is also seen with Hinata's father, Karyuudo, and appears to be friends with the third world's version of Yuno Gasai.