!Zwei/Reiji Azuma
->Voiced by: Kousuke Okano (Japanese, visual novel), Creator/TakahiroSakurai (Japanese, OVA), Creator/MiyuIrino (Japanese, TV anime), Creator/KeithSilverstein (English, OVA), Newton Pittman (English, TV anime)
* AntiHero: Though he is fully aware of the consequences and misdeeds of his actions.
* BadassInANiceSuit: During his time as an assassin he's commonly dressed in finely-tailored dark suits.

!Ein
->Voiced by: Creator/OmiMinami (Japanese, visual novel & OVA), Creator/AyahiTakagaki (Japanese, TV anime), Creator/MelaLee (English, OVA), Creator/LindsaySeidel (English, TV anime)
* EmotionlessGirl
* InnocentFanserviceGirl: Ein doesn't care about walking around naked in front of Zwei after having a shower.

!Cal Devens/Drei
->Voiced by: Creator/SatomiKoorogi (Japanese, visual novel), Creator/MiyukiSawashiro (Japanese, TV anime), Creator/BrittneyKarbowski (English, TV anime)

!Claudia McCunnen
->Voiced by: Creator/KikukoInoue (Japanese, visual novel & OVA), Creator/AyaHisakawa (Japanese, TV anime), Creator/CindyRobinson (English, OVA), Creator/ColleenClinkenbeard (English, TV anime)

!Mio Fujieda
->Voiced by: Creator/AmiKoshimizu (Japanese, TV anime), Creator/LeahClark (English, TV anime)

!Scythe Master
->Voiced by: Creator/KenNarita (Japanese, visual novel), Kazuhiro Nakata (Japanese, OVA), Creator/IsshinChiba (Japanese, TV anime), Dave Mallow (English, OVA), Creator/KentWilliams (English, TV anime)
* DubNameChange: The English Dub of the OVA switches his name around, changing it to "Master Scythe."
* FourEyesZeroSoul: The TV series and subsequent remake gave him glasses.
* MadScientist

!Lizzie Garland
->Voiced by: Creator/AiOrikasa (Japanese, visual novel & OVA), Creator/AkenoWatanabe (Japanese, TV anime), Creator/MeganHollingshead (English, OVA), Shay Moore (English, TV anime)