Volume 1

Devils' Line Volume 1 was originally published in Japan by Kodansha, Ltd. on September 20th, 2013. It consists of chapters 1 through 6 (which are called "Lines") and 6 bonus 4 panel comics. It was published in English by Vertical Comics on May 24th, 2016.

Dark Side
While riding the train home with her friends Miwako Toda and Shouta 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. Yuuki sites DNA evidence found at the scenes of three murders that points to Akimura. At this point, Yuuki 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 Yuuki as Akimura admits to his crimes. As Akimura reaches a clawed hand gently to stroke her face, Yuuki injects him with a tranquilizer and he passes out.

Anzai contact Takashi Sawazaki of F Squad to inform him that Akimura has been secured. Instead of taking him in himself, Yuuki decides to help a worn out Tsukasa get home. Yuuki tells her a little about devils and how they are very close to humans biologically and how he doesn't think the two shouldn't 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.

Safe House
The chapter about a month later with Tsukasa waking up mortified from a sexual fantasy dream with Yuuki. She goes through class in a daze, worrying about Akimura. Her friend Miwako accuses her of getting scared when people like her. Then, she starts to dwell on Yuuki and how he gave her her first kiss.

Meanwhile, Yuuki is dwelling on her as he watches her walk home. Apparently, he's done this multiple times since the incident in Line 1. He follows her and she catches him on her balcony. He says he's come to tell her that he can get her in to see Akimura if she wants. She is unsure because she's mostly been thinking about Yuuki. As he starts to leave, Tsukasa invites Yuuki inside.

Sawazaki contacts Anzai over the radio to tell him about the status of their current target. She is fleeing on foot. Anzai doesn't respond and goes inside. He can't get the memory of her blood out of his head and his eyes transform. While Tsukasa is making tea he falls asleep in her kotatsu.

He has a dream about him, and his two childhood friends, Tadaya and Yuuko (the target), playing in the snow when they were little. He wakes up suddenly and leaves, flustered at his lack of focus.

Sawazaki confronts a kitchen knife wielding Yuuko on the roof of a nearby building. He tries talking her down. Anzai arrives shortly and catches her off guard. She tells him about how much she loves her human husband. She only sucked his blood because of a stupid accident in the kitchen and she just hopes he's okay. Anzai criticizes her for thinking a human/devil relationship could work out. In the end, her husband is alive and he apologizes to her for not being more careful.

Tsukasa watches all of this because Yuuki forgot his utility belt and she followed him, thinking he might need it. He scolds her when he discovers this, but then apologizes when he realizes it's his fault. He decides to warm up in her kotatsu and falls asleep again.