This page contains unmarked spoilers. You Have Been Warned!

"The night is for fooling around. Let's have some fun, boy!"

In the black of night, one's character is tested. There are those who run from it, and those who grow from it.

In General

Episode 1

Nazuna takes Yamori for a flight across town, taking in the city lights and the night sky in the process. For the first time since he started skipping school, Yamori feels alive.
Nazuna: What do you think, boy? How do you feel?
(Beat as Yamori takes in the scenery)
Yamori: Awesome.
Nazuna: Isn't it?

Episode 6

Nazuna has chucked Shirakawa off the window of her apartment after Yamori asked her to make sure she can't go back to work. As Shirakawa realizes that she's about to die, what does Yamori do? He jumps after her and, in a Call-Back to the first episode, screams that no, she won't. He then stretches his hand and reaches out to Shirakawa, who takes it just as Nazuna swoops in and takes Yamori's other hand to slow down their fall. Judging from Yamori's calm expression, he completely trusted Nazuna to do just that.
- Between that and Yamori adamantly refusing to allow Shirakawa, a woman he's only just met, to return to a workplace that she loathes in the middle of the night, it's hard to tell which is bigger: his balls or his heart.

Episode 7

When another vampire is about to take a bite out of Yamori, Nazuna flies in and, before anyone can realize what has happened, rips the other vampire's arm off.
Nazuna: Hey, you... You think you can just take someone else's prey, you friggin' hussy?
- Moments later, she kicks the other vampire with tremendous force, which the other vampire is barely able to block. She then comments on how Nazuna's brute strength hasn't diminished. That's right: Nazuna has Super-Strength.
- After a second vampire shows up and abducts Yamori while the first one is gripping Nazuna's leg, Nazuna responds by kicking her across the face with her other leg while she's still gloating that taking Yamori was their goal, before furiously demanding to know where he's been taken. On your life, do not mess with Nazuna's man unless you are prepared to suffer her wrath.
- In the manga, by the time Seri rejoined the vampire council, she was battered and bruised all over and completely exhausted; Nazuna, on the other hand, didn't have so much as a scratch on her.
Kabura attempts to flirt with Yamori right in front of Nazuna, something Nico notes is a bad habit of hers. Nazuna is not amused.
Nazuna: (grabs Kabura's hand) Don't go touching my prey with your filthy hands, Kabura. Or I really will kill you.

Episode 9

Even though he doesn't stand to gain anything from it, even though Nazuna is not around to help him, and even though he's hopelessly outmatched, Yamori shoves Akiyama out of Seri's path before she can kill him. Mind you, Seri attacked with enough force to snap a door off its hinges; she would've destroyed Yamori if he had been too slow.
Though Yamori took Akiyama and ran from Seri, he fully expected her to not give up so easily. So what does he do? He pings Nazuna while he's talking with Akiyama, then distracts Seri by standing in her way, leading to Nazuna dropping on Seri just as she's about to attack Yamori.
Seri: You don't have to get it. You're gonna die now anywa-
Yamori: No. I won't let you kill him. I swear.

Episode 10

A small one for Yamori, who is able to deduce with minimal clues that no one was stalking Arisa and that she was taking pictures of herself.
- How did Yamori reach that conclusion? He noticed that the pictures were all taken when Arisa was alone, and that, considering the angles at which they were taken, the quality was too high; a stalker who happened to find a small window of opportunity would certainly have no time to worry about the quality. When he muses that the only people who look good in pictures are the kind who are used to taking selfies, he immediately realizes that the pictures were exactly that: selfies.
  Yamori: If I don't get to be a vampire, maybe I'll be a detective when I grow up.

Episode 12

After Anko points out the very real possibility that Yamori may never become a vampire no matter how hard he tries, how this will make him a liability to the other vampires, and how Nazuna may end up dead in the crossfire, she offers to protect him. Yamori rejects her offer when she points out that she would protect him by killing all vampires, refusing to see them as Always Chaotic Evil and sticking to his belief that vampires and humans can understand each other. Even when faced with the prospect of his own death, Yamori's conviction is nothing short of impressive.

Episode 13

When Yamori is left with the implication that Nazuna was injured while defending him, he immediately starts to leave the scene to look for her. Nico smugly tells him that Nazuna doesn't want to see him, but Yamori is having none of that: he angrily tells Nico to shut up and that he wants to see Nazuna.
He later runs into a couple of police officers who want to talk to him, presumably about Anko's call. Yamori decides he doesn't have time for them and jumps off the bridge he's standing on, somehow sticking a perfect landing before running off.

Chapter 103

Yamori, after suffering a beating at the hands of Mahiru, gets back up, calls out Mahiru for being blind to Kiku's past with men, flips him the bird, and awakens his newly acquired vampiric abilities before being stopped by Nazuna because he would have killed Mahiru if he'd actually used them.