Ako Hyakuya 「百夜 亜子, Hyakuya Ako」 was one of the orphans from the Hyakuya Orphanage.
Ako was a small child who had short brown hair with two side pigtails held with yellow bobbles and brown eyes.
As "livestock", she wore a dark choker with a tag and a sleeveless one piece dress with a hood. The dress had a design on the eyelet and black lining. She wore dark wrist bands on her both hands, and like the rest of the children, Ako didn't wear any footwear.
- Anime: Livestock wear shoes in the anime.
At some point in her life, her parents abandoned her at the Hyakuya Orphanage which was run by the Brotherhood of a Thousand Nights, a religious organization infamous for its cruel experimentation on orphans.
Shortly after Yu's arrival at the orphanage, the director suddenly began to bleed from her nose and mouth and collapsed to the ground.
The adults perished, Third Progenitor Krul Tepes led the vampire invasion on Tokyo. For the next four years, the orphans survived as livestock for the vampires in the vampire capital of Sanguinem, which is located under Kyoto.
- Ako 「亜子」 means "next child" with 「亜」 meaning "next" and 「子」 meaning "child".
- Hyakuya 「百夜」 means "hundred nights."
- She was the first orphan, who was killed by Ferid Bathory, once the Hyakuya family wanted escape from the vampire city.
- After Mika, she was the second orphan of her family, their blood was sucked by Ferid Bathory.