Dance in the Vampire Bund - Sledge Hammer no Tsuioku

From Seven Seas:
Dance in the Vampire Bund: The Memories of Sledge Hammer is a two-volume interlude between Dance in the Vampire Bund’s first fourteen volume story arc and the upcoming second part of the series, which will launch in 2014. The Memories of Sledge Hammer delves into the past to look at the doomed love affair of one of the Vampire Bund’s most deadly operatives.
Three months have passed since Princess Mina, queen of all vampires, has recaptured the Bund. The damage inflicted to vampire/human relations runs deep, but a peaceful postwar restoration is now underway. Yet appearances can be deceiving. Somebody is trying to kill government liaison Reiko Gotoh, but her lycanthrope bodyguard, Seiji Hama, is nowhere to be found. The mystery of Hama’s whereabouts can only be solved by examining the past, when the ill-fated couple first met. The past may be the key to saving Gotoh in the present and to the future of the Vampire Bund itself.