Mao, or "Mao-chan", is a polite and sweet 14-year old with notable light purple hair and sports a dress and sailor hat throughout the series. She is a very gentle-voiced, polite and perky person, 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.
Mao is shown to be a very pale frail looking young girl. She has very long light purple hair and light-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.
Her Apprentice Diary is the Hinata Love Diary which works similar to Yuno's diary, 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. She is also shown to have some skill with a knife.
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 dead corpse, she seems extremely distraut. The group rushs 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.
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.
retary'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 are then saved by Yuno Gasai. She later split up from the trio and they are not seen again until after Eleventh is thoroughly dealt with.