This Anime is set in 1930's Japan and Russian Siberia. It does a good job of portraying the setting. It blends in the vampire and the werewolf elements nicely, creating a believable alternative history.
The place were this show really shines is the characters. Especially Ryouko, who is portrayed as a strong young woman, but still believable.
But the second half of the show freezes all the character development except for Mikhail, and then by the last two episodes, the show completely jumps the shark, going into a mystical feel-good mumbo-jumbo land.
So overall, I would recommend it, but don't expect too much from the last few episodes - just watch them for the fight scenes & eye candy.