Benten is formerly one of Oboro's priestess. She joined his cause to rid of the weaklings in Ritenkyo. After she killed Saya's parents, she regretted her actions and found herself blinded by ochlocracy. She spared the infant Saya and her husband sacrificed himself to aid their escape. Benten passed onto Saya all that she knew, including her fighting style and how to be a "good woman". Additionally, Benten also made the girl her current weapons.
After the fall of the Razor Trio, she poses as a ninja who is intent on finishing her mission of killing Saya's family. They fight one another with Saya emerging victorious. Saya sees through the guise and cannot complete her revenge because of it. Benten explains her conflicted past and urges Saya to kill her as repentance. Saya gently renounces their relationship with one another and leaves on a positive note. After she departs, Benten, very proud of Saya, bids farewell to her kind daughter.