As of July 2026, B: The Beginning Season 1 aired in 2018 with 12 episodes — streaming now on Netflix. Full episode guide and where to watch below.
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B: The Beginning Season 1

2018 12 Episodes Action & Adventure · Animation ⭐ 8/10

If you want science fiction that respects its own premise, B: The Beginning Season 1 is available on and right now. The 1-season run is exactly the right length for what it is doing. An 8/10 rating says what the writing already makes obvious: this one works. Watch it for Asami Seto — the performance elevates material that could easily tip into self-seriousness. There is no real reason to keep putting it off.

B: The Beginning Season 1 arrived without much fanfare and built its audience the hard way — through word of mouth. What makes B: The Beginning Season 1 work is that the ideas never crowd out the people having them. In a world powered by advanced technology, crime and action sweep through the archipelagic nation of cremona. Chief among the major players is “Killer B” — a serial killer who has thrown the city into chaos. The stories of Koku, the protagonist, Keith, a legendary investigator of the Royal Investigation Service, and a mysterious criminal organization intertwine on the path to reach their objectives. Asami Seto and Hiroaki Hirata lead a cast that brings real weight to the material. It was aired in 2018. What separates B: The Beginning Season 1 from lesser genre entertainment is a willingness to let the concept cost the characters something. The consistency throughout is what elevates it — not every moment is the best, but none of them are a reason to stop watching.

Viewers burned by ambitious sci-fi that could not sustain its premise should give B: The Beginning Season 1 a chance. If you have run out of similar titles to watch, this is a strong next pick. It is a manageable watch, easy to fit into a single week. Asami Seto anchors it with a performance that makes the more abstract moments feel personal. If you have been burned by ambitious sci-fi before, this is the exception.

📡 Where to Watch B: The Beginning Season 1

🇦🇺 Australia
🇺🇸 United States
🇬🇧 United Kingdom
🇨🇦 Canada
🇳🇿 New Zealand
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🎬 B: The Beginning Season 1 — Episode Guide

E1
Episode 1
2018-03-02
Keith rejoins the RIS just in time to work a brutal double murder involving "Killer B." Then an unknown group steals a military vehicle for a rampage.
E2
Episode 2
2018-03-02
The RIS investigates a death that appears to be linked to Killer B, though Keith disagrees. Another body leads them to stake out a high-powered party.
E3
Episode 3
2018-03-02
Kaela battles the hackers as the poison gas release ticks closer. Keith drags Boris on a chase outside the city, pursuing Koku and one of the gang.
E4
Episode 4
2018-03-02
Koku and Keith both pay visits to the Royal Library. Afterward, Lily heads to Keith's apartment to discuss her thoughts on the Killer B case.
E5
Episode 5
2018-03-02
The team members grapple with the attack on one of their own, and the fact that there must be a traitor on the inside. Koku realizes who Canopus is.
E6
Episode 6
2018-03-02
After confronting Keith on the roof of the hospital, Koku agrees to meet him at a temple the next day. Keith is declared a murder suspect.
E7
Episode 7
2018-03-02
Minatsuki gives the OK for the others to attack Koku, but Keith intervenes to protect him. The RIS receives an ultimatum.
E8
Episode 8
2018-03-02
Eric implores Keith to return to the RIS, then suspends Lily in an effort to track Keith down. Minatsuki sends Takeru after Koku.
E9
Episode 9
2018-03-02
Keith turns himself in and the RIS decides to spend the few remaining hours laying a trap for the suspected head of Market Maker, using Lily as bait.
E10
Episode 10
2018-03-02
Koku searches for the zeppelin containing Market Maker and Yuna. Meanwhile, Keith, Eric and Kaela frantically search for Gilbert and Lily.
E11
Episode 11
2018-03-02
Keith sets off in pursuit of Gilbert once more. Koku finds the zeppelin and Minatsuki, but Laica escapes with Yuna in accordance with the prophecy.
E12
Episode 12
2018-03-02
The RIS races to the scene, while Keith confronts Gilbert at the old Jaula Blanca facility. Koku fights Laica for his and Yuna's survival.

🎭 Cast of B: The Beginning Season 1

Asami Seto
Asami Seto
Lily Hoshina (voice)
Hiroaki Hirata
Hiroaki Hirata
Keith Kazama Flick (voice)
Yuki Kaji
Yuki Kaji
Kokuu (voice)
Minoru Inaba
Minoru Inaba
Meyer Boris (voice)
Toshiyuki Toyonaga
Toshiyuki Toyonaga
Brandon Brian (voice)
Hiroki Touchi
Hiroki Touchi
Eric Toga (voice)
Toshiyuki Morikawa
Toshiyuki Morikawa
Ross Gilbert (voice)
Mitsuki Saiga
Mitsuki Saiga
Izanami (voice)
Gotou Atsushi
Gotou Atsushi
Richard Jean Henri (voice)
Kazuya Nakai
Kazuya Nakai
Kamui (voice)

📋 All Seasons of B: The Beginning

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