Saaya Otonashi is a main antagonist in the OneeChanbara video game and anime series. She is the half-sister of Aya, the series' protagonist, and possesses a deep grudge against her sibling. Saaya is notable for her vampiric powers and ability to control zombies, making her a formidable foe. Driven by revenge, she seeks to surpass Aya and claim her own power. Her complex motives and tragic background add depth to her villainous role in the series.