Voiced by: Mamiko Noto (JP), Colleen Clinkenbeard (EN)A badass immortal P.I. working out of Shinjiku.
- Anti-Hero: She's a good person at heart, but she has a rather icy personality. Plus, when she closes the door behind Saya to let her get eaten by various, zombie like creatures, she proves that, despite being on the side of good, she sure as hell won't forgive you for crossing the line.
- Back from the Dead: Or the closest variant for immortals. Her time spore is removed but thanks to Yggdrasil, her body begins regenerating around it.
- Badass in a Nice Suit: She's a tough-as-nails P.I who dresses in a rather spiffy three-piece suit.
- Bi the Way: Being immortal seems to loosen a person sexuality.
- Expy: Aside from the Distaff Counterpart bit in the YMMV tab, she bears more than a passing resemblence to Cima Garahau.
- Good Is Not Nice: Rin is nice, but she won't hesitate to end a bad guys existence in rather wicked ways.
- Identity Amnesia: After getting mulched by a jet engine and two decades of regeneration, she loses her memory.
- Immortality: Through From a Single Cell and being The Undead.
- Jekyll & Hyde: Although it's a subversion when her "bad side" is just Laura impersonating her.
- Jerk with a Heart of Gold: She can be pretty cold and sarcastic, but she's still quite caring towards those close to her.
- Ms. Fanservice: Boy howdy is she.
- Private Detective: How she makes her living.
Voiced by: Rie Kugimiya (JP), Jamie Marchi (EN)Rin's sidekick and fellow immortal. Works as a hacker.
- Badass Bookworm: An immortal hacker. Kind of a requirement.
- Bi the Way: She certainly has a thing for girls after getting a taste for it, but doesn't seem to dislike guys either.
- Girl Friday: For Rin.
- Hard-Drinking Party Girl: And she even holds her liquor better than Rin.
- The Smart Girl: The tech-savvy sidekick.
- Token Mini-Moe: A slight older example but she always looks younger than everyone else she's around.
Voiced by: Akira Ishida (JP), Todd Haberkorn (EN)A sadistic mother-effer who exists to make Rin's life (And any other persons in his way) an utter misery.
- A God Am I: Since he possesses traits of both immortals and angels, he views himself as the closest thing to a genuine god.
- Big Bad: Main antagonist of the series.
- The Chessmaster: Apos' plan has been in the works for centuries.
- Expy: Of Ryo Asuka.
- Evil Tastes Good: Just why is he so obsessed with causing as much pain to every immortal he finds? Because their time spores will taste so much better soaked with the memories of their pain.
- Faux Affably Evil: He'll put up a cheerful facade if he chooses, but it's just an act that hides an utter psycho underneath.
- From a Single Cell: Just like Rin.
- Hermaphrodite: It is unclear what the hell s/he is, but s/he apparently has two sets of genitalia.
- I Have You Now My Proud Beauty: Lord help you if you're an immortal.
- Karmic Death: He does gain a permanent position with Yggdrasil. By becoming part of it.
- Sadist: One enormous understatement...
- Self-Made Orphan: Kills his father, Tajimamori.
- Soft-Spoken Sadist: Rarely raises his voice, even when he has woman bound in chains.
Voiced by: Sayaka Ohara (JP), Clarine Harp (EN)A gun toting psycho and Rin's arch-nemesis.
- Alas, Poor Villain: Really, near the end of her life, she's been beaten up repeatedly and reduced to Apos' sex slave. It's something of a mercy when she finally dies.
- The Dragon: To Apos.
- Implacable Woman
- Professional Killer: Her main occupation.
- Psycho for Hire: Very psycho.
- Psycho Lesbian: Again, quite unhinged.
- Taking You with Me: A variation. After being crippled, she has Rin insert her Time Spore into Apos so she can torment him with her memories before dying.
- We Can Rebuild Her: Apos remakes her as cyborg in Rin's image (which he proceeds to have some fun with) and implants a time spore in her as well.
Voiced by: Rie Tanaka (JP), Monica Rial (EN)A scientist behind a number of cruel and terrible experiments
- Depraved Bisexual: She's a sexual sadist and rapes both Rin and Kouki in episode 1.
- Dirty Coward: After Rin overcomes her zombie hordes and leaves her at their mercy, Sayara cries and begs for her mother.
- Immortality Hurts: Apos grants her immortality sometime after episode 1. However she's preserved in the state she's in, and after being partly eaten by zombies and set on fire, Sayara is permanently stuck that way. She lamented that it took over 20 years for the technology to develop so she could walk again.
- Mad Scientist: At first she dabbles in Cloning (which produced a number of defective pained zombies) and later upgrades to bioterrorism.
- Sadist: She enjoys hurting people, and not just to scientific ends.
Voiced by: John Swasey (EN)A mysterious individual with ties to Rin.
- Chekhov's Gunman: A trait he shares with his descendents.
- He Who Must Not Be Seen: We don't meet him until the final episode.
- Our Angels Are Different: The only Angel who has no desire to eat someone. There's a reason for that.
- Star-Crossed Lovers: With Rin.
- There Can Only Be One: And Apos decides that Tajimamori ain't the One anymore.
- Walking Spoiler: His entire existence remains a mystery until the final episode. His status as the Guardian of Yggdrasil is a major plot point that explains Apos' motivations.
Voiced by: Nobuyuki Hiyama (JP), Robert McCollum (EN)A regular Joe who gets swept into Rin's world.
- And Then John Was a Zombie: To save an immortal, he became an Angel.
- Backup from Otherworld: His spirit helps Rin escape from Yggdrasil in the last episode.
- Bungled Suicide: Near the end of the first episode he is left with a gun by Rin who tells him that only he can choose what path to take. A gunshot is heard offscreen, suggesting he killed himself. However, he shows up at Rin's office the next day with a bandaged head wound. How he survived shooting himself in the head is never revealed, though it's likely he changed his mind at the last minute as he fired the gun and the bullet only grazed him.
- Deuteragonist: Serves as the viewpoint character, when Rin is not it.
- Cloning Blues: Though he gets over it after episode 1.
- Heroic Sacrifice: He consumes a Time Fruit to become an Angel and save Rin from Sayara.
- Killed Off for Real: Becomes an Angel.
- Locked into Strangeness: After attempting suicide and somehow surviving, he has a permanent spot of miscolored hair.