Mars Red Series by Karakarakemuri, Bunou Fujisawa, 藤沢文翁, 唐々煙

The historical vampire thriller that's now an anime!Aoi is an enterprising young journalist living in Taishō era Tokyo. Though the city is thriving, a string of murders have left people shaken. As Aoi investigates the crimes, she sees her old friend Shutaro. But Shutaro died years ago, didn’t he? What Aoi doesn’t know is that Shutaro is a vampire, working for the government as part of an elite unit. Can he protect Aoi from the dark forces battling for the city’s soul?

CREATURES OF THE NIGHTWhen a series a of grisly murders occurs in Tokyo’s red-light district, it hardly makes the news. The vampire soldiers of Special Forces Unit 16, however, believe that a vamp may be responsible. Suwa is usually the most reserved member of the team, but after he befriends a young girl working in a brothel, the search for the killer becomes personal. Will he find the monster before it strikes again?

The vampire soldiers in Special Unit 16 have faced down many monsters, but now they are up against the mysterious Defrott, a powerful vamp who looks like a young boy. When they face off against him, Kurusu and his brothers-in-arms discover that there might be an even bigger threat behind the scenes, one that makes them question their very existence! All will be revealed in the grand finale of Mars Red!