Rewrite this story and change shinobu to kanae and tanjiro to shinobu. These are characters from demon slayer so make it make sense. Tanjiro has been in need of some training recently, he wanted to get stronger so that he can defeat the upper rank demons. He's at the butterfly mansion and the other girls have gotten too easy for him to beat, so he decides to go straight to the top. "Hey Ms. Shinobu, can you please help me train?" Tanjiro asks. "Of course! I'll be right back." Shinobu says. She comes back and she is just in a bra and panties. "Wha-what are you wearing?!" Taniro says flustered. "It's much easier to move around in, now let's get to it!" Shinobu exclaims. She then charges at Tanjiro, tackling him onto the floor. 

Shinobu lands on him, she then straddles his throat and sits there. Tanjiro grabs at her, trying  to get her off but he can't. "Hey, no touching!" She demands. She grabs his wrists and pins them to the ground above him. To do this Shinobu had to lean forward so now her tits are hovering over his face. Tanjiro can't help but stare, but then Shinobu notices. "Hey, you perv!" She exclaims. She then jerks her hips forward, applying more weight onto Tanjiro's throat. He just closes his eyes and tries to escape. He starts kicking around and squirming, but soon his attempts start getting weaker and weaker. Finally Shinobu gets up off of him. 

She remains straddled on his chest but she turns around, facing his feet. "Deep breath, Tanjiro." She says. She then scoots back and sits on Tanjiro's face. Her thick ass covers his whole face, not allowing him to draw a single breath. He grabs at her ass, trying to push her off but he is already low on strength from her sitting on his throat. He tries to breathe but he is only met with ass and fabric. He tries to turn his head but she then puts her feet under his head, locking it in place and burying his face deeper into her ass. He starts to panic, kicking around and making every desperate attempt of escape he can, but nothing works. Finally, after about 40 seconds, he has almost passed out under Shinobu's ass.

She realizes he's going to go unconscious so she leans forward and puts one thighs on either side of his head. She waits for him to get enough breath in, and then she initiates the final act. She wraps up Tanjiro's neck with her thighs and she locks her ankles, trapping him in a reverse headscissor. She extends her legs and the pressure begins. Tanjiro's hands instantly go up to her thighs and try to pry them apart but to no avail. He starts kicking around again but she just ignores him. She stops squeezing with her thighs and grabs his hands, pinning them to the floor. "Y'know, Tanjiro, with skills and strength like that, you're never going to turn your sister human again." She says. Salt in the wound. She beats him up and then insults him like that. She then clamps her thighs together around his neck again, as hard as she can without snapping his neck. He can no longer move his arms, and kicking around isn't doing any good, so he is just stuck, waiting until he drifts off into dream land. Finally after about 8 seconds, Tanjro passes out between Shinobu's thick thighs, though she doesn't stop there. She keeps squeezing for another 10 seconds, just to make sure he's out for a while.