Line 1

Dark Side (悪の側面) is the first chapter of the first volume and the overall first chapter of the Devils' Line manga series.

Summary
While riding the train home with her friends Miwako and Akimura, Tsukasa Taira notices a man watching her in the reflection of the window. Akimura decides to walk Tsukasa home and on their way there he tries to admit his feelings for her, but then they notice the man from before is following them.

They make a run for it in an attempt to lose him and when they think they are safe, Akimura embraces a shocked Tsukasa. Suddenly, they are separated by the man who'd been following them, Yuuki Anzai, who calls Akimura a vampire. He grasps Akimura's head with the hand he had purposely cut with his teeth so that it is bleeding.

Akimura starts to transform at the sight of the blood and he fervently denies any intention to hurt Tsukasa. Anzai sites DNA evidence found at the scenes of three murders that points to Akimura. At this point, Anzai pushes Tsukasa aside to keep her away and she ends up slamming her head into the ground. Akimura says he's been taking medicine and tranquilizers in order to protect Tsukasa, and that he killed those three girls instead of her.

Tsukasa has gotten up and stands behind Anzai as Akimura admits to his crimes. As Akimura reaches a clawed hand gently to stroke her face, Anzai injects him with a tranquilizer and he passes out.

Anzai contacts a fellow officer, Takashi Sawazaki of F Squad to inform him that Akimura has been secured. Instead of taking him in himself, Anzai decides to help a worn out Tsukasa get home. Anzai tells her a little about devils and how they are very close to humans biologically and how he doesn't think the two should try to have relationships with each other. As he's telling her this, he notices her mouth is bleeding from when he pushed her away. He immediately transforms into a devil, licks the blood, and kisses her passionately. Before things go too far, he tranqs himself. The bags under his eyes disappear for a minute or two and he answers her question by telling her that he's a hybrid, with human and devil blood. He jumps from the staircase and leaves after trying to reassure her about Akimura.

Back in his room, we learn that this was the first time Anzai has had blood and he is very upset and disgusted with himself about it.

Tsukasa thinks longingly about Akimura as she lays in bed.

Chapter Notes

 * The main characters Yuuki Anzai and Tsukasa Taira are introduced.
 * Vampires exist and are typically called devils.
 * Anzai is a half human/half devil hybrid.
 * Devils crave blood, but don't need to drink it to survive.
 * When they see blood, devils transform (fangs, claws, red eyes) and become violent.
 * When devils drink blood, the bags under their eyes disappear and they look healthier.
 * Devils can be brought under control by using tranquilizers.
 * Tsukasa and Anzai share their first kiss.
 * This was the first time Anzai tasted human blood.

Characters

 * Tsukasa Taira
 * Yuuki Anzai
 * Shouta Akimura
 * Miwako Toda