It's short and it doesn't really have a complex plot as such.
It is basically the 'Defeated' detective Yuuki Shinjurou and his assistant/boss Inga solving mysteries.
The first few episodes are quite boring from the mystery point of view and are more into introducing the characters. In these few episodes, the culprit seems quite obvious and the only reason to watch them is to be able to understand the final few episodes.
Episode 7 onwards(if I remember correctly), the main plot involving the Bettenou is revealed. These last 5 episodes were the reason why I liked UN-GO as a mystery genre anime because these were the ones where the culprit wasn't so obvious and with his assistant/boss not by his side anymore, Yuuki Shinjurou was completely dependant on his own skill to figure out everything.
Overall, this anime could have been a lot better if it had a better plot and not-so-obvious culprits. (However, it might be that I was able to figure out who the culprit was, after having read so many mystery novels XD)
But jokes apart, it was not as good as the other mystery genre animes I have watched so far. I would recommend you to watch this before starting any mystery series because this one doesn't have a very complex story line like the other mystery genre animes out there.
