From [MangaHelpers](https://www.mangaupdates.com/groups.html?id=48756242591): In Edo Period Kyoto, Japan, the low-ranking samurai Amano Moritake serves the noble Hinonishi family. The Hinonishi family has become poor, but they still have a family treasure, an Awataguchi Hisakuni sword. Moritake is the guardian of this great treasure, and he protects the family from those who would want to take it from them. While in the service of the Hinonishi house, Moritake passes his days with the head of the family, Harusue, and his daughter Kaoruko. Together with the Hinonishi family, Moritake does his best to resolve each situation that comes their way.

Rio has lived at a convent with other girls since her parents died when she was very young. The girls live as well as they can, making secret trips at night out to the convenience store to get junk food. On one of these trips, Rio trips over a boy lying in the street. He doesn't want to go to the hospital so she sneaks him into the convent. When she wakes up that night to find him leaning over her bed, she is shocked to see he has fangs. But is he really a vampire?