Yumi Hayakawa (早川優美, Hayakawa Yūmi) is a student at Matabi Academy and the main character of the series. She is the owner of Kansuke.
Yumi is a young teenage girl of average height. She has brown eyes and long black hair that is braided on either side. She is most often seen wearing her school uniform.
Though clumsy and slightly silly, Yumi is also very kind and friendly. She loves knitting and often makes outfits for Kansuke.
Four years prior to the start of the series, she dove into a road to protect an injured Kansuke from an oncoming truck. After that, she took Kansuke in as her pet.
At the beginning of the story, Yumi Hayakawa is a newly-arrived first year student at Matabi Academy, which chose to attend so she could bring along her beloved pet cat Kansuke. While running late for the first morning assembly, Yumi bumps into Tsubame Akifuji and is instantly smitten with him. She arrives at the assembly where she makes fast friends with Nanako Uemura and witnesses all the members of the Student Council Committee, including Akifuji. However, for her tardiness and for being disruptive, she is scolded by the vice principal and made to clean the school statue alongside Nanako.
During a rainstorm, Yumi and Nanako are confronted by the newly-awoken Tsukumoisshu who threatens to remove Yumi's head so he may feast on her hair. However, she is protected by the barrier encompassing Matabi Academy. As the student council fight off his minions, Tsukumoisshu manages to break through the barrier. Suddenly, the spirits of Kirihime and Shirayuki appear before Yumi and Kansuke and grant them the power to defend themselves against Tsukumoisshu's attack. Yumi is marked with an emblem and she holds out her hand to call forth a ball of yarn that transforms Kansuke into a cat-human hybrid powerful enough to defeat Tsukumoisshu.
The day after the battle, Yumi finds Nanako nor any of the other students recall the events from the previous day. She is later met by Tsubame who explains that all the students, except for those blessed by Kirihime and Shirayuki, have forgotten the events due to a magical barrier around the campus. As he leads her to a secret room, he goes on to explain that each member of the student council also possesses powers bestowed by Kirihime and Shirayuki and that the school houses the seal of a great demon spirit beast named Kaen. Tsubame also says that, according to a prophecy, the one who defeats Kaen will be granted a single wish. Once they reach the secret room, where the other council members are waiting, they find that Kaen's seal has been broken.
Two weeks after Tsukumoisshu's attack, Yumi gets an ID tag for Kansuke and talks with Kotori Hasutani about the events regarding Kaen and, if they were to defeat him, what they would wish for. Suddenly, Yumi hears a noise and a giant boar spirit beast emerges from the woods. Yumi uses her powers to block an attack by the boar, leaving her and Kansuke unable to retaliate. Kotori and Musashimaru attack and nearly defeat the boar, but a giant millstone the boar was carrying catches Kotori in a vortex, threatening to suck her in and crush her. Yumi and Kansuke try to make a last ditch effort to save her, but Shin Kamio arrives at the last minute and slays the boar.
The day after the battle with the boar spirit beast, Kansuke goes off on his own wanting to become stronger. Yumi later goes looking for him and meets up with a cat who is looking for his friend Panta. The cat has no name and so she names him Shinpachi. While they are searching, Yumi observes that the yarn thread connected to Kansuke has vanished. The two make their way to the school library where, unbeknownst to them, Tsukumoisshu is trying to locate Sandou's room. Seeing an opportunity, Tsukumoisshu attempts to kill her, but is interrupted by the arrival of Tsukasa and Tsubame. While Yumi discusses the missing cat as well as an upcoming school festival with them, Tsukumoisshu observes that Tsubame possesses the key to Sandou's room. He considers attacking them, but decides to leave when Tsukasa's pet cat Raimu appears, meaning they would be able to fight back.
Yumi, Tsubame, and Tsukasa continue to talk until Tsukasa agrees to find Ponta. However, they are interrupted by the arrival of Rachi, one of the five sacred spirit beasts, who is possessing a female student. Rachi stabs Tsukasa and Raimu and traps Yumi and Tsubame in the library that has become infested with spiders. Yumi and Tsubame attempt to flee, but find no escape as they are told by Rachi that one spider bite will kill them. Tsubame tells Yumi to hold Shinpachi as he activates his power to take out a bunch of the spiders, but they are still overwhelmed. Tsubame gives Yumi the key to Sandou's room and tells her to escape there, but he is caught in one of Rachi's webs. Rachi then taunts Yumi, telling her that if she surrenders the key, she will kill her first, sparing her from seeing Tsubame die first, but assuring her that both of them will die regardless. Her resolve broken, Yumi gives up the key, but Shinpachi attacks Rachi, momentarily distracting her. As Rachi is about to eat Shinpachi, Tsukasa and Raimu intervene, revealing their time-and-space-altering powers. Tsukasa battles Rachi and nearly rescues the possessed student, but the time on his ability runs out. Rachi is about to kill Tsukasa, but Kansuke and Sakura finally arrive, allowing Yumi and Tsubame full use of their powers. Yumi uses her yarn to give Kansuke a new combat outfit that allows her to manipulate the yarn freely during battle. Yumi and Kansuke manage to bind Rachi giving Tsubame an opportunity to strike her weak spot; a jewel in her chest. As Rachi attempts to escape, Tsubame fires one more arrow that follows and strikes her, soundly defeating her. Yumi and Kansuke then use their powers to catch the falling unpossessed student.
Later, at the school infirmary where Tsukasa is recovering, Yumi and some of the student council members discuss the possibility of other possessed students. As Yumi and Kansuke walk back to their room, they meet up with Nanako and Shinpachi takes his leave.
Some time after the battle with Rachi, Yumi and her class are informed about the academy's upcoming cultural festival, in which she hopes to participate in drama along with Tsubame. Later that day, she meets up with her friends Nanako, Akari and Rie and finds Kansuke sleeping under a tree. That evening, during a sleepover, Rie tells the girls a scary story about an abandoned tunnel near the school. Supposedly, there was an accident in the tunnel where a girl's legs were crushed at the ankles and, due to the shock of losing her feet, the girl hung herself. And, according to the rumor, the ghost of the girl haunts the tunnel looking for her feet. After telling the tale, Rie receives a phone call from which a woman's voice is heard. Suddenly, a ghostly figure with no legs appears before them and abducts Nanako, claiming to want her legs to replace hers. Yumi and Kansuke give chase after the specter.
The two manage to track the ghost to the abandoned tunnel where they find shoes scattered about and the ghost still holding Nanako captive. They try to attack the ghost, but are caught in a thick fog and become separated in a forest that seems to come from nowhere. Apparently drawn by the sound of Kansuke's bell, Yumi soon comes across a lake and pulls Kansuke (who was caught by Daraku, one of the five sacred spirit beasts) out of it. However, the two are soon beset by an army of undead soldiers. Yumi and Kansuke attempt to fight them, but the soldiers get back up after every attack. The two attempt to flee, but Yumi is grabbed by the ghost girl who tells her that they must die so she can get her legs back. The girl claims that her ghost form never got her legs and Yumi surmises that they must have been burned away in the accident. As the ghost girl questions her existence, Daraku emerges from the lake and swats her away.
Yumi asks Daraku where Nanako is, but he only tells her that she will become a water puppet, just as he will do to Yumi and Kansuke. Daraku then explains the origin and history of the spirit beasts and their relationship with mankind. Daraku then creates a wave that knocks back and separates Yumi and Kansuke. Yumi searches for Kansuke, but stumbles upon Nanako and all the others who were abducted by Daraku. As it starts to rain, Kansuke, Kotori, and Musahimru find Yumi, who explains the situation. Above them appears what seems to be the humongous body of Daraku. Musashimaru attempts to fight him, but it turns out to be a giant storm cloud that electrocutes him. Kansuke catches Musashimaru's falling body, while Kaiya Yamamoto appears and rescues the falling Kotori. Nanako then awakens and Yumi goes to her side to console her amidst the chaos. Yumi and the others then make a final gamble, using Kansuke as bait, they pull Daraku out of lake with Yumi using her yarn as a fishing line, after which Shin makes the final strike.
After the battle, Yumi feels a great tension in her chest as, back at the academy, Kaen is possessing Tsubame. Daraku, still alive, utters his final words, claiming that the barrier will be reversed. Yumi falls to the ground crying, stating that she feels she has lost something precious to her. Yumi and the others depart and emerge from the tunnel and witness a giant hole in the sky, signifying the reversal of the Futakago Barrier. They then arrive at the academy to witness Tsubame, who has been possessed by Kaen, depart with the other spirit beasts through the Futakago Barrier.
After Kaen leaves through the portal, Shin and Kaiya chase after him and Yumi and others are left behind. Futaba Aoki uses her powers to heal Yumi's and the others' wounds and she tells them to rest and get changed and return in an hour if they are wiling to fight. Back at her room, Yumi changes and prepares to leave, but starts shaking and finds herself unable to commit to going after Tsubame. Kansuke gives her a pep talk, reminding her about the time she saved him from an oncoming truck, assuring her that she is courageous. Yumi confesses that it was actually her who hit Kansuke with her bike, giving him the scar on his forehead. Astounded by her confession, Kansuke nevertheless assures her that she is still an amazing person. Suddenly, Nanako, Rie, and Akari burst into Yumi's room asking for an explanation for where she went after the ghost girl incident. As they press Yumi, Kansuke yells at them and everyone is astounded to discover that Nanako, Rie, and Akari can understand him as well. They are interrupted though, by the arrival of Kotori who tells them that there is trouble.
Kotori explains that she tried to get everyone to evacuate the school, but the barrier surrounding the school has trapped everyone within. Yumi and the others are then attacked by a group of spirit beasts that had been summoned by Tsukumoisshu. Kotori and Musashimaru stay behind to fight two of the spirt beasts, while Yumi and Kansuke chase after another beast that got away, while also escorting Yumi's friends to the school gymnasium where all the other students have been gathered. Yumi and Kansuke are unable to catch the spirit beast in time as it attacks the gymnasium, but Futaba and Gekko intercept and fend it off. Yumi and Kansuke prepare to go through the portal via Tsukasa and Raimu's ability while Futaba and Kotori stay behind to protect the school. But, at the last minute, Shin arrives instructing all of them to go through the portal while he protects the school.
Yumi and the others go through the portal, taking them inside the Futakago Barrier, and they find themselves transported to a strange floating island with six floating pillars. Yumi is nervous about being so high in the air, but the group presses onward towards a palace in the center of the island. On their way, they find a hurt and abandoned Hisui and then are approached Kaiya who is revealed to have been possessed by the sacred spirit beast Kibao all along. Kibao battles them, but they are easily overwhelmed. Kibao then unleashes his true power in a final devastating attack, but Kansuke stands his ground, calling his bluff, revealing that Kibao never intended to kill them. Hisui explains that Kibao and Kaiya only fought them to stop them from going any further to protect Kotori. Kaiya explains how he became possessed by Kibao, and Kiba explains the history of the spirit beasts and Kirihime. He also explains that he wishes to fight alongside humans, but also wants the spirit beast to be freed. Therefore, he will attempt to stop Yumi and the others until the spirit beasts are released.
Akitaka Sandou Arc
After hearing Kibao's explanation, Yumi questions whether or not the destruction of the Futakago Barrier will cause her and the student council's powers to disappear. Unwilling to give up their powers, and knowing that they will not be able to come to a truce, Kotori decides to stay behind and fight Kibao while the others continue to stop Kaen. Yumi and the others press onward, but are met by Sakira, another of the five sacred spirit beasts. Before a fight between them can break out, the island starts to shake and the landscape breaks apart, sending them all plummeting downwards.
As she falls, Yumi finds herself transported to Futakago, one hundred years in the past, where she hears the voice of Kirihime. The princess explains that she is seeing an event that occurred between Kaen and her retainer Nobuhisa Sando, who had managed to survive for 900 years and had renamed himself Akitaka Sando. Sando offers to help Kaen release the spirit beasts under the pretext that the human population has grown too much and must be kept in check, and Kaen accepts. Kirihime then appears before Yumi and explains that Sando has become obsessed with reuniting with her and truly only wants to return the source of Futakago's power to the Earth's surface so he may do so. Kirihime then disappears and Yumi once again finds herself and the others falling through the air.
Yumi uses her yarn to create a parachute and series of hammocks to catch the others, including Sakira who is possessing a student's body. Sakira explains that the falling rubble is about to fall on their school and the gate has been opened, meaning all the spirit beasts have been released. Yumi and the others, realizing that they all experienced the same vision, discuss what to do, but Kotori and Kibao arrive, the latter having kept his promise to help the humans as soon as the spirit beasts were released. The two attempt to save the school below, but are intercepted by Hakubi. Before Yumi and the others can act, they are caught in a hypnotic spell by Sakira that renders them immobile and unconscious.
Sakira attempts to devour Futaba and Gekko, but are stopped by Tsukasa and Raimu's dream box ability. Once Sakira is defeated, Yumi and the others are freed from her trance. The group looks down and find that the rubble is actually swirling and coming together at one point. Yumi and the student council go before a large temple that has appeared and witness the rebirth of Sandou, who hid his body among Tsukumoisshu's skull collection. The spirit beasts attempt to destroy Sandou, but he only absorbs their powers, making him stronger. Sandou then explains that six large pillars have been around since before the spark of life itself and are the source of Futakago's power, as well as all magic and spiritual power. He plans to use the pillars to return that power to the world and become the leader of the spirit beasts.
After listening to Sandou, Yumi speaks up, asking him why he wishes to rule the world when it goes against Kirihime's wishes. He replies that he wants revenge for all the suffering he endured during the 1000 years he was continuously reincarnated, and now wishes to stand atop humanity. Sandou then abducts Yumi, knocking the others away and destroying Yumi's yarn, stating that she will be the "mother" needed to resurrect the princess. He then strips her of her clothing, knocks her out, and prepares her for a ceremony by which she will literally give birth to Kirihime. Sandou states that pillars will open a gate in Yumi's womb, through which the princess's spirit and energy will enter, making her develop and be birthed rapidly, which will kill Yumi in the process. However, the ritual is halted by Hakubi, who stops the last pillar from falling, and Tsubame who reveals that Kaen was never possessing him as he had seen through Sandou's plan all along. Yumi is then freed from her bindings and escapes with Kansuke who had just arrived. However, Sandou summons a giant stone golem that recaptures Yumi and forces the final pillar into the earth. Kansuke attempts to free her, but Yumi tells him to escape, saying that her stomach hurts. Kansuke then heads towards Sandou as Tsubame fires the Dagger of Futakago at him. The dagger hits a nearby stone structure and Kansuke retrieves and slices Sandou's throat with it. Sandou attempts to heal himself, but is unable to as the student council destroyed the magical construct by which he harnessed the power of the pillars. Sandou then withers away into an old man and Kirihime appears before him to finally take him to the afterlife. Kaen then destroys the golem, freeing Yumi. As they fall, Yumi and Kansuke are rescued by the spirit of Kirihime.
Amidst the destruction, Tsubame finds Yumi lying on the ground. She wakes up, saying that she has a cut lip, but otherwise is fine. The two look at the destroyed school and Tsubame says he always wondered what kind of man his great grandfather, Akitaka Sandou, was. The rest of the student council meet up with them, reassuring them that the rest of the students, including Nanako, Rie, and Akari are safe. Kaen then appears before them, stating that the spirit beasts have scattered and he will try to keep his existence a secret. Yumi then begins to cry as she realizes she can no longer hear what Kansuke is saying, nor can any of the student council members understand their cats. Kansuke becomes mad, but Yumi assures him that, even if she doesn't know the words, she can still understand him. She then lovingly embraces him.
Three months later, the students of Matabi Academy have relocated to an unused school and Yumi continues her life as usual, and wonders of the spirit beasts are still watching. Yumi attends her class where they discuss the upcoming school festival.
Her power manifests itself as a ball of wool (mirroring her passion for knitting), which can be used to transform Kansuke into his human form. The wool can also be reshaped into a number of other objects depending on the circumstance, such as a shield or a cushion. One drawback to her power is that it takes time to unravel, and isn't as strong when used in rapid succession.