Saya

Saya (沙耶) is the secondary antagonist of The Goddamn Samurai. Originally one of several Taimanins that went missing while investigating Tokyo Kingdom, she was apparently captured and turned into a super soldier by Oboro's clone. She now serves the clone, and helps Oboro in her plans to mentally break Asagi and Sakura so they can turn them into living weapons just like her.

Personality
The experiments done on her changed her personality dramatically. Saya may have the appearance of a cute teenaged girl, but she is clearly insane. She might act like a goofy, yet polite, child most of the time, but she is still a depraved rapist.

Asagi and Sakura Igawa
She is a genuinely polite person that doesn't hold any real malice toward the Igawa sisters. She even admits that she actually likes them. However, between her insanity cause by Oboro's experiment, and her desire to have a "sister" just like her, Saya isn't above tormenting them.