B: The Beginning
Genius investigator Keith Flick rejoins the royal police force just as serial killer "B" emerges. Mysterious youth Koku may be an ally, or a target.
Starring Asami Seto, Hiroaki Hirata, Yuki Kaji
Watch "B: The Beginning" on Netflix released in 2018. It's a animation and sci-fi & fantasy show, and has a rating of 7.1 out of 10 from Imdb which is usually fine for this kind of show.