Kotori Mizuki (観月小鳥 Mizuki Kotori) is a character and one of the main protagonists of the Yu-Gi-Oh! ZEXAL manga. Although not Dueling, Kotori has a big role in the series, serving as Yuma Tsukumo's important friend and main support.
Kotori is part of Yuma's circle of friends, together with Tetsuo, Cathy and Takashi. At school, when Yuma kept challenging himself with impossible tasks with his "kattobingu" spirit, Tetsuo usually made fun of him, while Kotori was always worried. She reprimanded Yuma for being so reckless, but at the same time encouraged him, and was always on his side. Kotori once asked why he tried to do those impossible things, and he answers that the important thing is to challenge, and that when he is with the pendant his parents gave him, he felt like he could do anything.
One day, Kotori and Yuma found that Tetsuo had been forced to Duel a guy nicknamed Shark, and after being defeated, he took Tetsuo's Deck. Yuma confronted him, but Shark took his pendant and broke it. Enraged, Yuma challenged him to a Duel. Shark accepted, and said that they will Duel on Sunday, in the train station.
Later, Yuma kept searching for the other half of his broken pendant until late in the night, with Kotori by his side. Tetsuo appeared and told Yuma not to Duel Shark, as he would never be able to win, and that it was a problem of his. Yuma declined, saying that that's already a problem of his as well, as Shark broke his most important thing. Tetsuo gave Yuma the other half of the pendant, saying that he found it accidentally. However, it can be clearly seen that Tetsuo was searching for it as well, judging by its hands. On Sunday, Kotori and Tetsuo supported Yuma during his Duel with Shark. During the Duel, as Astral appeared to Yuma, Kotori worried about him talking "to himself". Yuma asked if she and Tetsuo couldn't see Astral, and they confirmed it. Later, when Yuma defeated Shark, Kotori and Tetsuo congratulated him.
In the next day, at school, Yuma was greeted by Cathy, Kotori, Takashi and Tetsuo. Takashi said he heard that Yuma won against Shark, surprising him, while Tetsuo said he let it slip. Takashi said he didn't know that Yuma was actually a good Duelist and that he must have hidden, undiscovered talent. Cathy grabbed Yuma's arm, saying he must have won through his power of "kattobingu". Kotori asked if Cathy isn't getting a little too close to Yuma and Cathy asked why she had a problem with that. Kotori and Cathy began to yell at one another, as Yuma falls over. At that time, Tokonusuke, eavesdropping nearby and watching Yuma, determined that his next target will be Yuma, and he believed something fishy must have happened for Yuma to beat Shark. He soon later runs over to Yuma, asking him for his autograph, and gives him a "Baby Tragon" card in gratitude.
The next day at school, Kotori told Yuma that Tokunosuke was looking for him a minute ago to challenge him to a Duel after school. She told him to be careful, as Tetsuo had heard many bad rumors about Tokunosuke. Yuma refused to believe this, saying that Tokunosuke was a good guy. Later, Yuma met him, telling him that he'd be happy to Duel. He responded that the Duel will be held where everyone can see. Yuma and Tokunosuke then Dueled. However, Tokunosuke used "Baby Tragon" to take control of Yuma's "Numbers", and revealed that the paper which Yuma signed was an agreement to bet on their best cards for the Duel. Yuma used "Baby Tragon" together with "Needle Swordsman" and managed to win. After the Duel, Yuma offered Tokunosuke the "Baby Tragon" card back, but Tokunosuke let Yuma keep it. Tokunosuke then became friends with Yuma and the rest of the gang.
After a Numbers holder attempts to rob a shopping mall, Kaito Tenjo a Numbers Hunter, defeats him and absorbs his "Number", alongside with his soul. Akari was investigating about the incident and commented with Yuma about a "Numbers Hunter". Later, at school, Astral discussed with Yuma about that "Numbers Hunter", worried about what is his goal and if he would come after Yuma. However, Yuma didn't worry about that. As it was raining, everybody was in the class, wanting to go out and Duel. One of Yuma's classmates than suggests going to the gymnasium, and all rushed out towards there. In the way, it started raining more, and Kotori was getting behind. Yuma then told her to run, but when she was crossing the street, a truck was passing on it. Yuma immediately ran and pushed her out of the way, but now the truck was going to hit him. Yuma then notices he wasn't hit, and Astral finds the time has been stopped. Then, Kaito, the Numbers Hunter, appears. Kaito explains his servant robot, Orbital 7, has caused the time freeze, and then, forces Yuma to a Duel, betting his "Numbers" and his soul. With no option, Yuma Duels him. However, even with his "kattobingu" spirit, he wasn't a challenge to Kaito, who dominated the Duel. When Kaito was about to win, Orbital 7 warns him his brother Haruto is in bad conditions, and Kaito immediately cancels the Duel and goes after him. With that, time goes back to normal, and Yuma falls on his knees, shocked on noticing how weak he is.Upon his loss to Kaito, Yuma's spirit is totally broken. Kotori gets upset with that, and tries to do many things to cheer him up. First, she tries to Duel, but she fails at using the D-Pad. Next, she tries to jump over 20 blocks in the P.E. class, but hits her head at them. Later, she leaps form a high height at the pool, but ends up injured. Yuma and the whole gang take her to the hospital. Yuma yells at her saying to stop doing that dangerous things, and she yells back that its because Yuma is becoming a loser, and cries. This makes Yuma awkward, and he says that she is right and that he will "kattobingu" back from that on. Cathy than gets jealous after Kotori hugs Yuma, and start arguing with Kotori. Yuma explains about the "Numbers", and the gang start discussing about that. They then come up with the idea of creating the Numbers Club in order to help Yuma. The Club then start looking for clues about the "Numbers", and Tokunosuke finds an information that "Numbers" exist in the Heartland Theme Park. By that way, they take Yuma to the park. However, the owner of the park, Mr. Heartland, hired three Numbers Hunters, who work in the park, collecting "Numbers" secretly disguised as employees.
Yuma and his friends than go to the park, and have fun in many attractions. After trying many of them, they go to a roller coaster attraction called "Nature Crooz", owned by a popular character from the Theme Park, Captain Corn. However, Captain Corn is one of the Numbers Hunters from the park, and as soon as Yuma enters in the roller coaster, he splits the wagons, separating Yuma from his friends, and challenging him to a Duel betting the "Numbers".
While Yuma and Corn Duel, Kotori, Tetsuo, Cathy and Tokunosuke notice Yuma's missing, and try to leave to look for him. But Captain Corn traps and almost kills them. However, Cathy's agility saved the group, while Yuma managed to defeat Captain Corn. Yuma and his friend then meet, and eat Captain Corn, who exploded into a pile of popcorn due the explosion of Yuma's "Hope Buster".
When Astral absorbs Captain Corn's "Number", Mr. Heartland appears and reveals he is hunting the "Numbers" to destroy Astral's home, the Astral World, because it is evil, and Astral is the "messenger". Yuma defends Astral, which makes the others do as well, but Mr. Heartland clicks his fingers, and a kind of door opens in the floor, making them fall in the "Speed Field", another attraction in the Theme Park. There, they find another Numbers Hunter from the Park, Thunder Spark, who challenges Yuma to a "Speed Duel" in the "Speed Field". While Yuma and Astral Duel Spark, Kotori and the rest of the gang watch it from a helicopter offered by the attraction. When Yuma fell in the water, both Cathy and Kotori jumped from the helicopter to the water, doing "Catbingu", in order to save him. However, he soon came back on his own, making the girls' effort useless.
After jumping into the Speed Field's river field in order to save Yuma, Kotori and Cathy are soaked. They are inside a dark stone building, and notice a door in the opposite site of the building. It appears to be a dressing room, full of female clothes. Cathy and Kotori then borrow a dry dress for each. Tetsuo comments that the girls kept arguing the whole way to there, and that its odd how they suddenly look like friends, while Takashi complements saying that the situation shows how complicated a girl can be. Cathy and Kotori then ask Yuma if they are cute with that clothes, and start arguing about that. Seeing that the girls have a good relationship, but keep arguing, Astral comments that its seems to be complicated to maintain a friendship. Takashi and Tokunosuke then notice a big door there, which they all pass by, entering a dark room, decorated with lots of creepy dolls, and featuring a big stairway leading to a Doll House. Suddenly, Cologne comes down the stairs, holding a candlestick. She welcomes them to her House of Dolls, and Astral notes she is Princess Cologne, who was known as the mascot of Heartland. They then notice she was also an enemy, and she confirms it, saying that Yuma and Astral won't get out of there. But when Cathy replies saying that a short like her cannot intimidate them, Cologne notices Kotori and Cathy are using clothes from hers. The girls try to excuse, but Cologne doesn't listen to them, and enraged, throws the candlestick, which surrounds them with flames, and challenges Yuma to a Duel.
During the Duel, Cologne reveals about her past. Cologne was once a doll, who was bought by a rich girl. However, that rich girl soon bought a new doll, forgetting about Cologne, and abandoning her. She was then sent to the disposal plant of Heartland. There, Dr. Faker picked her up and gave her a life. And then, crying, yells that she doesn't want to be a miserable doll anymore. This feeling strike Yuma and the others, making Yuma hesitate about the Duel. At that time Cathy notes she was the girl who abandoned Cologne. She gets awkward and confused about what to do, but when she decides telling the truth, Kotori says that she was the one who abandoned her, and apologizes. She did this so that Cologne soothed her anger, and that Yuma could concentrate in the Duel, but Cologne knows she is lying, and gets even angrier, throwing oil in the fire surrounding them so that it gets higher, almost hitting them.
When Yuma defeats Cologne, the impact of his "Number" throws her to inside the Doll House, which was in fire. At that time, Cathy dove into the flames and tries to save her, saying that she was the one who abandoned Cologne, and had to save her. Cathy's noble attitude makes shocked Yuma and Kotori. In her haste, Cathy accidently grabbed one of Cologne's dolls instead of Cologne. This time, Yuma decides to go save Cologne, but, who comes out of the Doll House carrying her in his arms is Grandpa Demetto. Cologne's soul was supposed to leave her body, but Demetto gave her his own soul, which allowed her to stay alive. While he sends Cologne out of the fire towards Yuma, he is engulfed by the flames together with the field.
Cologne mourns the death of Demetto, who she loved. As she had nowhere to go now, Yuma invites her to live with him in his house. Cologne asks him why he is doing that, and he answers saying that everybody that Duels him becomes his friend. Cologne accepts Yuma's invitation, becoming friends with him and the rest of the gang.
Later, Yuma and the members of the Numbers Club gather in Cathy's house. Everyone get impressed at her mansion. Astral comments that it is much better than Yuma's house. Cathy then tells Yuma that if he marries her, all that would be his, and Kotori doesn't believe she said that and yells at her. Cathy then presses a cat paw-like button, which opens a door leading to a big room, with many researchers and big computers. Cathy explains that as an apology for the trouble she caused, the Numbers Club's headquarters would be established there, where they can look up mysterious phenomenons happening throughout the world, and therefore, locate the "Numbers". While the guys get amazed on the technology and say how Cathy is really put into it, Kotori sarcastically says Cathy is letting her money do the talking, while she replies saying asking if Kotori could do that. The Numbers Club then start helping Yuma, wearing new super hero-like outfits.
After Kaito Tenjo's Duel with Hishakaku and Yuma Tsukumo and Orbital 7 saving Kaito Tenjo from a fall that would have killed him, Kotori visited Yuma and Cologne at Yuma Tsukumo's house and they both hearing screaming in Yuma's room, so they checked it out and they saw Kaito knocked out by Cologne. After Kaito woke up, Kaito was wondering why he was saved by Yuma Tsukumo and Orbital 7, but he was interrupted when he saw Astral in the room, so he turned on his Duel Gazer tattoo and tried to Duel, but found out that Yuma hid it away, so he could rest. Kaito also looks at Kotori thinking that she did while she was shocked and nervous. They went to the kitchen, so Kaito could eat and have the energy to find Haruto, but they failed twice when they were trying to cook eggs. Fortunately, Akari and Haru arrived with food and everyone started eating. Akari asked Kaito how he knows Yuma, so Kaito told her that he was a natural born Duelist, but was interrupted when Yuma accidentally spit out his food and Yuma changed it to Karaoke Duet and they sang a little as an example. A hour later, while Kaito and Yuma were talking, Akari told Yuma to take Kotori home and Yuma got dressed and they went Kotori's house.
Once Yuma dropped off Kotori five feet from her house, Shadow knocked out and kidnapped Kotori to lure Kaito, Ryoga and Yuma to a trap. Once a ransom note on a blank card was retrieved to Kaito and Yuma at Yuma's house, Kaito left to battle Shadow to save Kotori. Once Yuma arrived at the spot where Shadow and Kaito were Dueling, Kotori woke up and Yuma was holding her steadily to get up from the ground. The next day, Yuma was in a hurry after school to find Kaito and Shark before something bad happened and Kotori was trying to catch up to Yuma. Before she could, time stopped and as Kotori didn't possess a "Number" she remained stopped in the edge of the sidewalk while Yuma was watching Shark and Kaito Duel and later while Yuma Dueling Shadow.
A few weeks later, the whole gang went to the hospital to see Tetsuo getting out of the hospital feeling better after his injuries from his Duel. Once Tetsuo finds out that the Numbers' Club hasn't disbanded, but they were doing their own thing during the time he was in the hospital. Yuma also told Tetsuo that he wants to partner up with Shark and Kaito to beat Kyoji Yagumo to end the Numbers War. Tokunosuke showed Kotori and the others that he bought tickets to the opening of the new Heartland Tower in Heartland and everyone was shocked and happy. Everyone said yeah together with their hands up.
The next day, Kotori and the others along with Cologne arrived at the opening of the new Heartland Tower, so they hurried up as soon as they saw the line build up. Kotori and the others were wondering where Yuma went and Kotori and the others were shocked when they saw him on the field about to Duel Kaito.
After finding out that Yuma Tsukumo was Dueling Kaito Tenjo, Yuma asks Kotori and the others to find Haruto while he distracts Kaito in a Duel. After Kotori and the others found Cologne and Luna while they were looking for Haruto, Luna explains what is going on with the Duel. Tetuso sends Kotori, Cathy, Cologne, and Takashi to find Haruto while He, Luna, and Tokunosuke look for Dr. Faker and stop the device. Kotori and the others travelled through the Disposal Facility to find Haruto, but Cologne told them that it was a shortcut to the real location of Haruto’s room. When Kotori and the others got to the top of Heartland Tower, they were shocked to see that the tower was torn apart after Kyoji had destroyed it. Out of nowhere, Kotori and the others saw that something flying toward them and also crashing. Kotori and the others realized that it was Orbital 7, who crashed in the middle of the four. Kotori begged Orbital 7 for help to find Haruto and that he is being held hostage by Kyoji and Orbital 7 agreed to help find Haruto.
When Kotori and the others arrived at a location where Orbital 7 used a computer to find Haruto, the robot found Haruto in the device where the new Duel stadium was located. Tetsuo had Orbital 7 fly Kotori and Luna to the device. Kotori and Luna went through the entrance of the device where Haruto was strapped to be "kept alive", but actually being used to activate the device to gather the number cards’ energy to activate the device.
Kotori told Yuma to stop the Duel after they found Haruto in the device, but Kyoji had told Kaito that if he stopped the Duel, that Haruto will die. Orbital 7 tried his best to break the cross monument to get Haruto out of there, but he kept failing since the monument was strong enough to survive Orbital’s hits. Kotori screamed at Kaito in order to remind him that he is a good guy after he saved her previously. Kotori got worried for Haruto, but the others showed up and helped break the cross monument in half and Orbital substituted for Haruto's life-support system. Kotori was worried when the device didn’t stop after they released Haruto. Although Yuma told Kaito that Kotori and the others saved Haruto, Kaito was possessed by his "No. 95: Galaxy Eyes Dark Matter Dragon", forcing Yuma to win to release Kaito from the control of the "Number".
Kotori and the others are sucked into the vortex and protected from debris by Luna's pendant before Yuma Tsukumo, Kaito Tenjo, and Ryoga Kamishiro (manga) Duel Kyoji Yagumo in the Otherworld Ocean. Kotori cheers Yuma on as the three duel Yagumo. Kotori realized that Yuma had convinced the others to join him in the Duel against Yagumo. Kotori worried for Yuma and the others as the Duel continued. She was pleased to see that if Yuma's attack went through they would win the Duel, but Yagumo managed to hang on with 100 LP. E'Rah appears and took over the Duel for Yagumo, overpowering them with "E'Rah Monsters" and launching a direct attack at Yuma, causing Kotori to scream Yuma's name. She was horrified when Shark took the attack himself and was killed as a result. Kotori and Tokunosuke were pleased when Kaito managed to drive E'Rah back with a loop combo, but E'Rah managed to survive and Summoned "Anti-Hope, God of Despair", defeating and killing Kaito as well. E'Rah then offered Yuma and Astral the chance to surrender, and in recognition of her tenacity she would make the souls of Yuma and his friends part of her new world, claiming that it was the only way for them to survive, much to Kotori's shock. Kotori led her friends in denying that they wanted to be part of a world like E'Rah's and they encouraged Yuma and Astral to win. She was pleased when Yuma revived Shark and Kaito's new "Numbers"; "No. 37: Hope Woven Dragon Spider Shark" and "No. 38: Hope Harbinger Dragon Titanic Galaxy", but E'Rah blocked most of their efforts to defeat her until Yuma and Astral united using ZEXAL, Summoning "No. S0: Hope ZEXAL" and transforming into the monster to defeat E'Rah.
After the Duel, Astral returned most of Yuma's friends to Earth with the exception of Kotori and reclaimed all of the "Numbers" except "Utopia", which Yuma refused to give to Astral to prevent him from sacrificing himself to seal E'Rah permanently. Yuma asked Kotori to stay with him as he ha from the beginning. During the Duel, Shark, Kaito and Yagumo explained the flow of the turns to Kotori, and Kotori eventually realized that Yuma was deliberately recreating parts of his prior Duels with Astral. Although Yuma was able to win, Astral used the effect of his "No. 93: Utopia Kaiser" to take "Utopia" from Yuma, and the two bid a sad farewell. Astral sent Kotori and the others back to Earth before turning to stone. Kotori resumed her normal life at Heartland Academy.
- ↑ Yu-Gi-Oh! ZEXAL Rank 1: "The Name's Yuma!!"
- ↑ Yu-Gi-Oh! ZEXAL Rank 2: "A Mysterious Life-Form?!"
- ↑ Yu-Gi-Oh! ZEXAL Rank 3: "Astral!!"
- ↑ Yu-Gi-Oh! ZEXAL Rank 4: "The Light of Hope!!"
- ↑ Yu-Gi-Oh! ZEXAL Rank 5: "Plot and Counterplot?!"
- ↑ Yu-Gi-Oh! ZEXAL Rank 6: "Yesterday's Enemy is...!?"
- ↑ Yu-Gi-Oh! ZEXAL Rank 7: "Numbers Hunter!!"
- ↑ Yu-Gi-Oh! ZEXAL Rank 8: "Galaxy-Eyes Photon Dragon!!"
- ↑ Yu-Gi-Oh! ZEXAL Rank 9: "Kaito's True Skill!!"
- ↑ Yu-Gi-Oh! ZEXAL Rank 10: "New Enemies!!"
- ↑ Yu-Gi-Oh! ZEXAL Rank 11: "Heartland!!"
- ↑ Yu-Gi-Oh! ZEXAL Rank 12: "Corn's Secret!!"
- ↑ Yu-Gi-Oh! ZEXAL Rank 13: "The Second Assassin!!"
- ↑ Yu-Gi-Oh! ZEXAL Rank 14: "Victory Conditions!!"
- ↑ Yu-Gi-Oh! ZEXAL Rank 15: "A Shared Bond!!"
- ↑ Yu-Gi-Oh! ZEXAL Rank 16: "The Third Enemy!!"
- ↑ Yu-Gi-Oh! ZEXAL Rank 17: "Frankie!!"
- ↑ Yu-Gi-Oh! ZEXAL Rank 18: "Kaito Again!!"
- ↑ Yu-Gi-Oh! ZEXAL Rank 19: "Messenger from the Moon!!"
- ↑ Yu-Gi-Oh! ZEXAL Rank 20: "A Three-Way Battle!!"