This prequel reveals the events around when Shinjuurou and Inga first meet and the events leading to their current arrangement.
What I Liked: Gives a more detailed background of Yuuki, Inga and Bettenou that was unfortunately lacking in the series. Especially liking the display and explanation of Bettenou and Inga's powers. What I Didn't: Story-telling and world-building's still a little patchy, and the constant time-skips don't help. At least the episodic nature of the series is missing from this OVA.Final Verdict: A great prequel that does a superb job of filling in the gaps with Yuuki, Inga and Bettenou. Unfortunately, not much more history is given to the terrorist events that took place in the world of Un-Go and the constant time-skips become tiring.
This is a prequel to Un-Go, but is much more understandable along with the series. We get to the backstory behind Yuuki and Inga, as well as better insight on Bettenou and the grudge Yuuki holds against Rinroku Kaishou. The events taking place are mentioned at points in the series, although without much of an explanation.The story itself is quite interesting, ranging from personal struggle between the ideal self and the actual from military/political conspiracy. However, it is not fully explored and the constant back and forth in time can get unnecessarily confusing.When it comes to the animation, there is nothing particular or especially exciting, but it is well made. It has a specific style and once you get into it it's fine, just like many other anime out there.The soundtrack is the same as the series, fitting and with some interesting tracks. It grabs attention at the right moments and plays a minor background role at others. Personally I liked it to the point of listening to it afterwards.Can't really comment on the characters, since it is not a standalone movie. There is not much character development, apart maybe from Yuuki, but there is no time for that either. It is assumed that you either have watched or will watch the series and most characters are plot devices for the story to work and Yuuki's past to be better explained.Overall, it's a fine film, but without outstanding points. If you liked the series you're probably going to like this one as well and I'd give it a 6.5, maybe leaning to 7.
I've said pretty much everything in my review of Un-Go. It is rare to find an addition to a series that is not only a prequal but also brings down the entire series. This episode manages it amazingly well. Other than that it is pretty good as it answers some questions about Yuuki and Inga. I just wish that they hadn't used Bettenou for it.