Ayato is sleeping on the couch when Yui arrives. At first, she thinks that he is dead because he had no pulse and tries to call an ambulance, but as soon as she takes her phone out, Ayato gets up and snatches it away from her. He says that she is too noisy. After that, Ayato pulls Yui to the couch and attempts to bite her. However, he is soon interrupted by Reiji, who tells him to take his activities to his private room. Yui then frees herself from him and runs to Reiji for help at which Ayato gets pissed off. Later, when everyone is asking Yui how she came here, Laito and Kanato licks her face and say that she tastes sweet. Ayato protests and tells them to not touch his things while addressing himself as Ore-Sama as he was the first to find her. Hearing him addressing himself like that, Subaru out of nowhere comments that he is tired of Ayato calling himself Ore-Sama. Ayato gets angry and demands Subaru to show himself. A few moment later, he teases Yui when she attempts to get her phone back from him but soon Subaru approaches and breaks the phone which makes Ayato annoyed. Then, when Yui is trying to escape from all the brothers, Ayato encounters her and tells her she can't escape. Then he, along with Laito and Kanato, hold her and lick her skin. After Shu breaks the picture to stop them, Ayato reaches out puts her on the floor and asks her if she is ready for this.
When Laito attempts to feed on Yui, Ayato stops him by pushing him off Yui's bed and tells him not to touch his things without permission. Laito says that he is being rough at which Ayato tells him to shut up. Later at school, Yui ends up in same class as Ayato and Kanato. When she goes to her class, she notices that no one is there except for three of them and it's food preparation time. Ayato then takes Yui to the kitchen and demands her to make takoyaki. Yui at first refuses, but ends up making it. When Ayato is done eating it, Yui starts cleaning the dishes and asks Ayato for help. Ayato then stands behind her and, when Yui turns to look, she gets scared and tries to run away. Ayato corners her and starts sucking her blood. Yui begs him to stop, but he doesn't listen and continues sucking her blood right until Reiji comes and says that Ayato is a disgrace because he never thought Ayato would do something like that at school. Then Reiji tells Ayato to bring her home. Ayato gets extremely mad and takes Yui to the swimming pool room and throws her in the pool. Then he demands her to tell him that he is the best of all. Yui is unable to swim and begs him for help. He at first stands there and watches, but soon he had a flashback about his past and after that he finally jumps in to help Yui. He grabs Yui by arm staring at her then kisses her, after which Yui wakes up. He then smells her from neck to shoulder and then bites her and suck her blood underwater. After that he pulls her out of water and tells her that her blood is flowing in his body and it totally overwhelms him. Yui then pleads him to make it stop, after which Ayato leaves and tells her that's enough for today.
After dinner, Ayato out of nowhere appears in Yui's room when she is checking the diary she found in the abandoned room and demands that she let him suck her blood, but Yui tells him that she can't right now as she is feeling dizzy and was about to take a bath. Ayato gets mad and violently gives her kiss marks on her neck and chest. He then tells her to go take bath as he don't want to take any troubles before she leaves he tells her to not keep him waiting or else he will punish her. Later after Yui comes back from bath, Ayato tells her that she is late, as he has been waiting to feed on her from long time. Yui tries to stop him but he tells her to just submit to his feeding. As he is about to bite her neck, he see's that she has already been bitten buy someone. At first he suspects its Reiji, but then realizes that it had to be Shu. He then goes to game room where Shu is sleeping on couch and angrily asks him if he is trying to pick a fight with him. Shu doesn't responds at all which makes Ayato even more angry so he challenges him to a game of darts and Laito tells them the prize will be Yui. Shu at first rejects and tells Ayato that he couldn't care less about her at which Ayato gets angry. After a harsh remark from Reiji, Shu finally agrees to play. Shu wins the game and gets Yui as a prize which makes Ayato extremely disappointed.
Ayato makes a brief appearance in this episode when Kanato is strangling Yui. He tells Kanato that Reiji is looking for him at which Kanato releases Yui. Yui thanks Ayato but he tells her not to get any wrong idea and then he holds her neck to drink her blood but stops and tells her he is not into it today because he's tired.
Yui sees a young Ayato, Laito and Kanato trying to catch bats. When Kanato is crying about the bat getting away, Ayato and Laito assure him that they can catch it again. Just as they about to go again, Ayato is called by his mother Cordelia. She was wondering if this is where he was and tells him to come with her. Cordelia tells Ayato that he has to go back inside and study but Ayato doesn’t want to because all he’s done is study. Cordelia tells him that she doesn’t want any excuses and tells him to go to his room. He asks why Kanato and Laito get to play while all he gets to do is study. Cordelia says that it's because Ayato isn’t like other children but Ayato says that he wants to play more. She then yells at him asking how many time must she tell him that he is the successor and does he even understand what that means then she wants him to tell her what he must do. Ayato lowers his head and says that he must become number one and must become better than anyone. Then Cordelia asks what happens if he fails. He says that he’s not his mother’s child so he will be sunk to the bottom of the lake. Cordelia then calls him a good boy and that he is worthless to her unless he is number one. She then says that worthless boys must spend eternity at the cold, damp bottom of the lake, all alone where no one can help them. She then says that if he doesn’t want that to happen then he should go to his room and Ayato runs away. In the present, Ayato wakes Yui up. She asks where they are and he tells her that they are in the underground waterway. She then asks how she got there and he asks if she doesn’t remember and tells her to stay away from this place when it rains. She then points to a door and asks what’s behind it but he tells her that she doesn’t need to know. He notices the cut on her finger and asks what happened to her hand. She also wonders how she got it and then she has a flashback of her trying to pick up the rose. Ayato agrees with Laito that the scent of the blood is certainly potent and that he’s smelled it before. Ayato tells Laito to step aside when he corners Yui and he bites her. He then says that’s the flavor he remembers and then Yui’s heart makes a loud pulse and he backs up and Yui says that her chest is hurting again. Ayato allows Laito to bite after that. Ayato looks at him and get annoyed and he pulls down the left shoulder of her nightgown and bites her. He then stops because he says he’s bored of this and leaves. In the final scene, Ayato sitting on a ledge looking at the rain.
Ayato appears with Kanato behind Laito. Yui asks what their mother's name was and Ayato says "Cordelia." In a flashback, Cordelia is visibly wounded and we see Ayato's clothes soaked in blood. Ayato says that it's a shame that these clothes are ruined and he really liked his shirt. He says that the clothes are soaked in her blood and then licks his hand. He says that her blood is sweet and licks his hand again. He says that her blood is delicious and says he wants more. Later on when Yui is in her bed, Ayato suddenly appears on the bed but he doesn't want her to look at him. When she tries to protest, he puts his arm around her and puts her back down and tells her not to disobey him.
When 'Cordelia' awakens, all the brothers feel it, Ayato especially. He is sitting on the couch in the entrance hall when he feels it. He runs into Yui's room to see if she is there but he finds her rosary cross discarded on her bed. He picks it up and clenches it tightly.
Ayato appears behind the two and asks what's going on. ‘Cordelia’ says that it’s been a long time and Ayato angrily asks what they have done. After Cordelia leaves, Ayato asks Richter what he did to Yui. After Richter tells Ayato what happened, Ayato asks if Cordelia's heart is inside Yui. At the dock, Ayato walks up behind her and she asks what he will do now; will he kill her again? He responds by saying that he used to be a bad swimmer. She says that she remembers, but thanks to her that he’s improved greatly. He then tells her that it’s her turn. But she just says that as he should know, she is an excellent swimmer. Ayato then pushes her into the lake and as she sinks, she wonders what is this and is shocked to realize that Yui can’t swim. Up above, Ayato tells her to get lost and walks away but stops when he hears Yui say his name. He sees Yui manage to get hold of the dock. Back on dry land, Yui asks why she was in the lake and this dress. Ayato just looks at her then gets closer. Yui says his name again but he tells her to just be quiet because his body is unbelievably parched and wants her blood then bites her. As he drinks her blood demandingly, he comments that her blood is so filling now; there is no comparison then bites her again and they both end up lying on the ground. He switches from sucking her collar to her neck and says the this is a first for him; as long as he has her blood, he’ll never want then he bites her again. Yui asks him to stop but he says that her blood is too sweet to give up. He continues by saying the she belongs to him; her blood, her heart, her body, her soul, her everything. He leans down and tells her to devote her blood and life to him and is about to kiss her when Laito and Kanato appear. Both Ayato and Yui get up but Yui is so scared that she runs into the forest and Ayato block their path so they won’t follow her. Laito comments how it’s not nice for Ayato to be greedy. Kanato agrees by saying that they want a taste of her but Ayato tells them to shut up because it’s not his problem.
Ayato appears and tells both 'Cordelia' and Richter to shut up. He tells Richter that Yui belongs to him and says that he can’t touch her without him say-so. Richter grabs a sword on rack nearby and yells at Ayato not to interfere. He swings the sword at Ayato and cuts part of his necktie. Laito then throws a sword to Ayato who catches it and tells Richter that his free ride is over and he’ll make him regret coming here. Richter asks what Ayato thinks he can do about it. Their swords clash but Ayato is pushed back and Richter stabs his left shoulder. Richter then pulls the sword out and when the blood comes out into ‘Cordelia’s’ view. Ayato drops his sword and falls on one knee. Richter points his sword at him and tells him to stay still but then we hear Yui says Ayato’s name. When he looks at her, her eyes are back to normal. Yui breaks free from Richter and grabs the silver knife. She runs and holds the knife above her heart and everyone is shocked and surprised. Yui says that now no one will get hurt and stabs herself. Ayato catches her as she falls but Richter is angry, says that the heart is his, and swings his sword at them. Ayato then stabs him in the midsection and Richter drops his sword and falls to the ground. Ayato yells at Yui, asking her to open her eyes.
Ayato is seen holding Yui's body. He asks Subaru if he can pull out the knife now and goes ahead to do it but Subaru stops him and pulls it out himself.. Ayato is now in a room where Yui is laying down, and he questions Shu if there's any way to drive Cordelia out of her. He is now sitting on the arm of the couch and turns around when he hears Yui reacting. He walks up to her and tells her to wake up. When Shu says that she can't awaken with the power of a vampire because no vessel has ever endured the process, Ayato comments on how it's different this time. Reiji then comes into the room with a bottle in his hand, which causes Ayato to question what he has. When Kanato gives Reiji what he needs for the remedy to be complete, Ayato smiles and asks if that did the trick. Ayato then has the remedy in his mouth, giving it to Yui via her mouth. He calls her by her real name and then she wakes up. He greets her and she asks him what she's doing here. He tells her that she doesn't need to know that.
When Yui wakes up, Ayato startles her when he comments that she's finally awake. She sits up to see the triplet brothers on her bed. Ayato tells her that he just woke up and he's thirsty, and orders her to let him suck her blood. He urges her to let him have it already as he goes closer to her. Ayato goes in to bite her neck, along with his brothers Kanato and Laito who try to bite Yui as well, but the three of them are stopped by Reiji and all of them are now seen in the limousine. Ayato complains how he had to interrupt when it was just getting good. He leans in closer to Yui, saying that he's parched and can't take it anymore, but Reiji interrupts him once again. Ayato yells at Reiji to shut up and stop getting in his way. Subaru calls him a nuisance, and Ayato angrily asks him what was that. Laito tells him to not make a fuss and Ayato who was obviously irritated shouted at him that he'll do what he want. Then the limousine crashes. Ayato had saved Yui and asked what is this as he watched the limousine go up in flames. He puts down Yui and tells her that she's heavy. Yui thanks him and he says it's whatever and that he just didn't want to lose her blood. All of them see the Mukami's up on the cliff and Ayato angrily questions who they are. Once the brothers conclude that they're also vampires, Ayato says that so this is a declaration of war, commenting on how it sounds like fun and grins.
Ayato sits down in a chair, angrily stating that he can't find Yui anywhere. He questions where did she go.