(I'm guessing she's going to Shintaro, not Sengoku?)
She's allowed out, though many are surprised that one of the best candidates would leave after the most difficult tests were completed. As she returns to Castle Yokuboo, the blonde is told that Shintaro is currently outside the complex, in the city. She's led into a room, nonetheless, and at her request the guards bind and gag her, tying a blindfold over her eyes.
She's alone for quite a while, nothing but the sound of her own breathing for company, when she hears the door open. At first, she assumes that it's Shintaro returning, but the gait is far too light and feminine. The newcomer slides the door closed, before slowly approaching Kina. "Mmmm, so you're the Yokuboo's delicious little morsel, eh?" The voice is silky and seductive, and as Kina hears it, she can't shake the feeling that she wants to hear more. The woman moves her hand forwards to open Kina's robe, exposing her breasts. "Just perfect." The woman caresses Kina's breasts, pinching the nipples in just the right way to fill the blonde's head with pleasure. "We're going to have so much fun together. When Shintaro is gone, I'll keep you around me all the time."