There are really only a few useful pieces of information that can be said about KKG. 1) This is a bridge between S1 and S2 of Darker than Black. 2) Even though it came out AFTER S2 you NEED to watch this before you watch S2 or else S2 will make no sense. 3) KKG is good but it sets the stage for all the weird shit that happens in S2. Many people (myself included) were disappointed with S2. Looking back, I may have been happier with the series overall if I just stopped after S1. Most people will find it hard to stop after S1 but stoppingafter KKG is impossible.

4) Don't expect S2 to answer any of the questions you may have at the end of KKG.

5) The action is pretty good and the chemistry between Hei and Yin was done well.