The story is very thin, and as mentioned already here. I will just keep it short. Demons vs Angels as the Prologue itself defines, but this anime is purely for the art, the original hand drawn masterpiece is what makes this OVA shine. It's very similar to the art style of Mr. Kawajiri. And the mystery of the plot keeps it going. That's why you won't even remember the prologue once you are in the narration.
Extreme gore is missing for a Cyberpunk work like this, but it will still satisfy for the ones who are looking for something very dark, as the opening itself hits perfect. The screenplay is fantastic, since the story is nothing much to write about the intriguing screenplay is what keeps this alive and makes you lit. The background score which plays in some sequences matches pretty well for the scene, it's very subtle so you will definitely feel it's effect.
Wish they had a 3 part OVA for this work, it would have been excellent as the depth is lacking in the work, characters of the Long siblings should have been explored more and the beautiful women esp Chen, her dominatrix dress in the start gave away strong vibes of extreme sinister thoughts, and female body is shown in the work thoroughly but with a bit of hesitation they should have at-least extended the scenes and went more deeper like Yōjū Toshi. But probably wanted to have a distinct style which the staff definitely achieved, the Demon's capturing of prey is somewhat reminiscent of lovecraftian style, H.R Giger inspired, Vulva with thorns and tentacles, I mean you can clearly see what their intent was, they really held back in my eyes, still a great achievement.
Just watch it for the Art and the Atmosphere, the old anime works like this have always captured 10/10 in the impact, there's simply no way Japan would have such works, it's a lost art. And the best part is it's Timeless so you watch it anytime as you wish.
Thanks for your time.
