Shou, the older brother, and Saya, the little sister, only have each other. The two of them lived happily, enjoying their peaceful lives together. That is, until Saya was bitten. When bitten by a pure-blood...

Since they were kids, Saya has always looked up to her kind, gentle older brother, Shou. He always looked after her, put her needs first, they spent all of their time together, and ultimately he was the only...