Kazuya Kujou is a Japanese learning abroad at the Saint Marguerite Academy. When he discovers a mysterious doll looking girl named Victorique, their adventures together begin as they start solving mysteries that even the police can't solve.
Gosick and Dansai Bunri no Crime Edge share a very similar character constellation: a beautiful, fragile girl who is excluded from society and a boy who is connected to her somehow. Together they become involved in various mysteries.
The difference is that Gosick is set in the past and has less emphasis on the fantastic elements.
Both of the series have the same gothic theme from the 19th century. The main characters are very alike, Vitorique (Gosick) and Dalian (Dantalian no Shoka) are very much alike because of their intelligence and their fashion. Both of them like to wear a very gothic lolita dress. As for the main male characters, both Kujo and Hyui are looking after their girl.