Title: Sweet Blood
In a world dominated by vampires, human rights and freedoms have been severely limited. Humans and vampires are segregated, with very few select humans given passes to travel through and in vampire areas without being accompanied by a vampire. Jinosuke is one of those few humans. He's a potter whose work is impeded by the deteriorating relationship between humans and vampires. Unfortunately, his most recent job has just been canceled due to his sponsor pulling out.
Frustrated and unemployed, Jinosuke travels through a vampire district, aimless and trying to determine his next course of action. Even with a pass, it's not easy going through the streets of vampire districts, as all vampires have silver hair, and humans don't. So, Jinosuke is constantly being watched and talked about. He's hardly bothered by the attention until he ends up in a sparsely populated area. There, he is ambushed, confined, and then sold in a human auction for vampires. This is very illegal, but as the product being sold, Jinosuke has no choice but to go along with the process.
In the end, Jinosuke is purchased by a youthful-looking vampire named Noi, a human anthropologist. Thankfully, Noi doesn't want to force Jinosuke into being food but would like to make a trade. In exchange for his blood and knowledge of humans, Jinosuke can continue to work and live under Noi's protection. It's not ideal, but it's better than the alternative, so Jinosuke accepts. What Jinosuke doesn't expect is for the feeding to feel so good. As they share more time (and fluids) with one another, Jinosuke begins to suspect it wasn't a coincidence that Noi was the one to purchase him.