|This article contains spoilers! Proceed with caution!|
Growing up Sayuri was forced to spend her time studying due to her strict parents. She had no time for friends or fun but forced herself to deal with it in order to please them. With some help from her Grandfather she managed to cope with it and eventually was able to score some free time, in which she befriended Yuuya, Kanna, and Haruka.
After the dog attack the group had been separated, with Sayuri being shipped off to a brand new school. Unknown to her friends, the stress of losing them and being forced into an arrange marriage was enough to send her on a rampage throughout the school, landing her in a psychiatric hospital.
After Yuuya developed feelings for a classmate and began to ignore the girls, they reunited in order to stop it and confronted him when he attempts to get together with the girl to confess his feelings. She told Yuuya that she came to agree with Haruka, in that they refused to let anyone ruin their bond and the only choice they had was to rid of this girl. As they made threats and prepared to harm her, Yuuya attempted to get the girl to safety until a train car collided with him.
Since then everyone has acted as though the incident never happened, except for Yuuya, who spends his time wondering how it exactly happened.
(For alternate decision endings and killings view Sayuri's page)
Sayuri suggests they make a haunted house, which gains support until she goes into graphic detail over horror classics and various things they should make sure to focus on so that its convincing. Everyone refuses after nearly throwing up and they settle for a new idea, much to her disappointment.
To get supplies Sayuri goes with Yuuya but decides to look at some jewelry. An envious and concerned Haruka and Kanna track them with the aid of a device Kanna got, watching as Sayuri attempts to convince Yuuya to wear a Couples necklace set. As they exit the store they quickly spot the duo and Sayuri is quick to accuse them of belittling their friendship and trust. She coldly tells them off for this and crushes the device, then decides to forgive them after Yuuya calms her down.
Eventually their efforts pay off when Yuuya gets an email awarding their hard work by throwing a celebration in the Clubs honor, hosted by the Mayor for everything they done for not only the Festival, but aiding City Hall and the whole town. Sayuri is delighted with the news but expresses disappointment shortly afterwards- revealing she had homemade sweets she wanted them to eat together. Not wanting them to go to waste, Yuuya offers to share a couple with her back in the Club Room and she accepts, although he warns her that he wants to pay the sick Kanna a visit. She agrees and they return to the room.
After eating a couple of the treats Yuuya finds himself overwhelmed by tiredness. He tries to fight it off but Sayuri assures him its fine, allowing him to even use her lap as a pillow for a small nap. Yuuya refuses but the drowsiness quickly takes over.
A few hours later Yuuya wakes up to realize everyone in the building is leaving and its dark out now. Upset, he asks Sayuri why she didn't wake him as promised, but she claims she had intended to- but only when the gates were getting ready to close, a detail she failed to mention earlier. She tries to play it off and starts to leave as Yuuya happens to notice his newly groomed nails, and in his haste to hurry up he trips over a trashcan. He quickly cleans the mess before noticing there isn't any nail clippings within it.
Eventually the Ceremony approaches and Kayako is found murdered. Yuuya locks himself up at home for days until he is able to recover from the shock and returns to school. To his alarm he finds out the girls are happy Kayako is out of the way, which alarms him and causes him to realize that not only do all three feel the same way, but they have certainly changed for the worst. With no other choice Yuuya decides to avoid them and the Club, but this leads the girls to wonder what they did wrong and they get upset.
The next day Yuuya is confronted by Sayuri, who claims he obviously hadn't meant what he said and tries to force him to confide in her truthfully. He refuses and runs off, only stopping to notice she keeps the same vacant expression as she had from before. He also finds her spying on him later on while speaking to the class president, Shizuka, only to run away after he notices her.
Concerned over Sayuri's strange behavior, Yuuya painfully learns he was right in suspecting something was wrong when Shizuka is threatened by a pair of scissors held by her. Quickly Yuuya pulls her out of harms way as other students begin to arrive. Shizuka attempts to calm Sayuri down but she refuses to listen, noticing the time and heading to class instead.
In hopes of figuring things out, Yuuya invites Sayuri to have lunch with him on the roof- but once again he finds himself really tired after eating. He drifts off to sleep until Kanna and Haruka arrive to find them together; both angry because they made a mutual agreement to stay apart from him when not together. Calmly Sayuri states she didn't care, because unlike them she took initiative to get what she wanted. Yuuya listens as they speak, then hears Sayuri state that he forced himself on her. It then dons on him that he always feels tired after eating her food, realizing she must have been drugging it this entire time. Unfortunately all he can do is listen, still drowsy and frightful over her mentality and causing any further damage.
Eventually Yuuya is able to convince the girls he hasn't chosen any of them, which calms down Kanna and Haruka. He is able to tell how upset Sayuri is but she acts fine and goes on her way. But throughout their school day she continues to act weird- escalating when she begins to grow suspicious over Kanna and Haruka.
Later in the day Yuuya attempts to speak with Sayuri, but he bumps into Shizuka once more. He sees a cut on her leg and realizes yet again Sayuri attempted to harm her, though she claims it to be nothing before going on to confront her when she spots her approaching. Sayuri, not willing to listen and desperate to rid of her "rival" pushes her down the stairs- but luckily Yuuya catches her as Sayuri takes off.
The following day Yuuya arrives to school with Sayuri, mentally commenting on her strange references to "knights" when they met up earlier. They find Shizuka being taken away in an ambulance, alarming Yuuya and wondering what could have happened. He runs to her classroom to find out that one of the students witnessed it, revealing that a pair of scissors flew out of her desk and stabbed her in the eye.
Right away Yuuya realizes the scissors belong to Sayuri, recalling the past few attacks she attempted and he confronts her in an attempt to make her stop. He also makes a mental note to warn Kanna and Haruka upon realizing there isn't any way to stop Sayuri like this.
If Yuuya avoids any of the possible bad endings (getting him or someone else killed) Sayuri eventually kidnaps him and takes him to a secret location that nobody can access. She goes on to reveal that she is the murderer, going on to point fingers at the other girls in Yuuya's life as the reason for him "being unawakened yet" as the powerful prince of light she is sure he is. She believes in her absense they manipulated him, so she had to hurry up and rid of them when she could return. Fearful for his friends, Yuuya makes a threat to kill himself should she even try anything, and is able to barely manipulate Sayuri by claiming he would be aware of her crimes, should she commit any. He then tries to convince her to release him.
Unfortunately, Sayuri is too far gone to believe he isn't being controlled by demons and refuses to let him go. She goes on to bring up where she got the idea of the Mascot Suit, stating it was an armor to protect him from demons and to awaken him. But now she worries it isn't enough, since the demons must have snuck into "their new home" and warns him to be careful. She then raises her paranoia, deciding for the time being he isn't allowed to have food or water, since a demon wouldn't want to stay in a weakened body.
Desparate to escape, Yuuya attempts to scream and call for help to try to get someone, anywhere, to hear him. Although Sayuri ends up mistaking this as the demon leaving and pleased with her work, she allows him to relax on her lap and get some rest. She also makes sure to give him water, but by now Yuuya has begun to feel nothing. He knows getting Sayuri back to normal is impossible, but he is still too weakened and is sure he would die before he could get to safety or fix everything, and believes there isn't any reason to hope for a miracle.
Suddenly, Sayuri decides to allow Yuuya to rest in peace when he requests a little time alone. Realizing she never took his phone, he quickly makes a call to the Dective and explains everything. The Detective promises to come out there and check things out, but after hours of waiting he never shows up, causing Yuuya further stress until he awakens to hear him and lets him inside; just as Sayuri steps into the room. To Yuuya's shock he finds out Detective Kudou was onto her plans this entire time, and that he's been working with her in an attempt to keep her in place without bloodshed and any harm to herself after she takes off from the room. He wants Yuuya to play along in order to see to it nothing bad happens. He has no intent of Sayuri going to prison or getting legal trouble for her sins, considering how easy it is to set people up. With that, the Detective decides to spend time with them as he has the day off and he can keep an eye on Yuuya, knowing he's too weakened to make a run for it.
For a while, Yuuya notices how playful and calmed down Sayuri has become with Kudou's support. She dotes on him once more, preparing nice meals for everyone and feeding him- but while Sayuri is really happy, Yuuya is more or less placid and attempting to put up with it. Eventually Kudo is left alone with him again and they resume discussion, with Yuuya unsure of how he truly feels about Sayuri now, but wants to believe she can indeed be saved. Kudou, although knowing its risky is glad Yuuya hasn't given up on her and decides they can work together to help her.
But after a few days, Kudou decides he can no longer stand by and let Sayuri continue on in her madness. One early morning he uses a pair of keys to get Yuuya to safety, but before they go he decides to explain why Sayuri has become like this. They both know its a risk that she could catch them- but they decide to get it out of the way now, with Yuuya too curious to ignore it. After he listens to Kudou he realizes maybe a single shred of hope is still there, and she can be saved. He plans to help Yuuya escape, then he will convince Sayuri to turn herself in, alongside himself.
Just as they open the door to leave, they find a distressed Sayuri standing there. She breaks down after deciding she must take care of the Detective and grabs her scissors and lunges to attack Yuuya first. But to his shock, Yuuya is shoved out of the way, towards the escape and Sayuri's scissors stab through Kudou. Shocked, everything freezes as Kudou endures the pain; which Yuuya is sure he could have prevented due to his training. He tries to understand why he did this, listening as he attempts to get Sayuri to snap out of her delusions. Unfortunaletly this drives her further berserk and she resumes stabbing him as Kudou attempts to convince Yuuya to run, knowing she's too distracted to give chase and hesitantly, Yuuya does as demanded, taking off and not daring to stop or look behind him.
Yuuya runs as far as he can into town, deciding he has to figure out what to do now, but with many options unsure of what to decide. The only thing he can determine is that he doesn't return to home since Sayuri would most-likely show up there. He decides to go to school and confront his friends, hoping they might be rational and understanding enough to help him.
At school Yuuya shocked everyone when he shows up suddenly, but he wastes no time in hurrying to get Kanna and Haruka outside to speak to them in private. As it turns out they were told he fled overseas to escape the charges against him, which he is able to determine was Kudou's doing to cover his mysterious vanishing. He brings the girls to their club room and confesses everything, including Sayuri kidnapping him and killing the detective, and how he used this to run away, and that she was the one guilty of killing Kayako.
At first the girls are shocked by this, but knowing how much Sayuri means to them they agree to help Yuuya try to calm her down. They wait for Sayuri to arrive, knowing she would most-likely follow after Yuuya or search in the places they often hung out at, and in no time she soon shows up. Right away they confront her when she tells Yuuya they should head back for home and wonders what is going on between the trio, but she fails to listen to them as they try to convince her that she isn't like this, stating that she is bound to Yuuya through their fates. Kanna challanges such a statement by asking her if she's really that insecure, and soon Sayuri asks Yuuya for his opinions, but after he answers it sends her into a berserk state and she brings out her scissors in an attempt to attack the others. Refusing to let this continue Yuuya gets in her way and is sliced on the cheek when he grabs her arm to stop her.
Snapping out of it, Yuuya tries to get through to Sayuri by telling her the fairytales she relies on are just pretend stories, then asks if her friendship with the others truly meant nothing. In this instance, Sayuri thinks about their past when Yuuya was able to cheer her up by reminding her of their friendship, and how much he, Haruka, and Kanna care about her. This allows Sayuri to finally realize how much pain she's caused everyone and she thinks back to the day the dog attacked them and the promise they made together.
As Sayuri drops her scissors, she begins to feel heavy remorse for everyone she's hurt, and how she almost killed Kanna and Haruka. Her concerns of losing Yuuya kept her from talking to the girls and they realize they did the same, wondering if speaking personally could have prevented everything that happened. Sayuri decides she must pay for what she did, and to everyone's surprise a new detective shows up- revealing he received an email from Kudou from a set timer. The email contained all of the details on the murder of Kayoko, but Yuuya is crushed to learn that Kudou wasn't able to be saved. With that the detective prepares to take her away, but before they leave the trio promise to see her, allowing her to leave with reassurance.
During the trial Sayuri didn't bother to plea innocent, appearing heavily remorseful for what she did. However, her lawyer, afforded by her grandfathers money had helped reduce her sentence. In this time, Yuuya still continues to hang out with Haruka and Kanna, but without Sayuri around they don't fight over him, and they only hang out sometimes. While he feels lonely, he knows they are still friends and one day they can all be together again.
Eventually Sayuri is released from jail, where Yuuya made sure to be there waiting for her- just as promised. She apologized to everyone who came to pay her a visit, from her parents to her teachers, her friends, even Shizuka. This surprises Yuuya, who reveals that because of the incident Shizuka had been hospitilized for some time and they were unable to visit her because of their connections to Sayuri. It wasn't until graduation that they saw her again.
Sayuri believes that it might have been due to Shizuka that she feels better now, mentioning how often she paid her visits. She decided to stop repressing herself for the sake of others, and has set in mind a goal for herself. She still feels guilt for what she has done, but she will do her best to make ammends. With that the duo decide to pay a visit to Dective Kudou's grave and Yuuya makes an oath to himself that he will continue to protect Sayuri's happiness.