Orochi: Blood

Orochi: Blood is a tale of two sisters: Kazusa, the older, perfect sister, and Lisa, her supposed inferior. Following a car accident, Lisa is saved by a girl named Orochi, who then mysteriously falls asleep for several decades. When Orochi awakens, she's being taken to a mansion where the two women live. Lisa is now caring for the ill Kazusa. What strange secret binds the sisters to each other, and Orochi to both of them?