Let Nemu continue.

Ichigo asked, "What sort of investigation are you talking about, Nemu?"
Hearing this indirect consent, Nemu began to undo her obi. Ichigo watched intently. He didn't know what to expect. For all he knew, her body would be made of gears and hardware underneath her clothing. Luckily, to his arousal, she exposed large human looking breasts to him.
"I have seen that in the Human World, as well as in Soul Society, that men have a fascination with breasts. I would like you to use mine in an appropriate manner."
Nemu then lowered her breasts over Ichigo's face and pressed them softly against him. Ichigo couldn't believe it. She was willingly giving herself to him. He might have pushed her back but when Nemu's breasts come into contact with his face he was stunned. They felt extremely smooth and delicate, they were not filled with gears and wiring like he'd feared. Curiosity made him move involuntarily to touch them. He squeezed them. The texture and density of them was also baffling. Kurotsuchi had created her in a more magnificent physique than any women would ever be able to obtain.
Ichigo was filled with masculine drive as well as lust. Since Nemu had given him permission to "use" her breasts, he let himself act freely and he began to massage her breasts and suck on her nipples. Nemu could feel her body temperature rise as Ichigo did this. Her face began to get red and her breathing became heavy.
"Mr. Kurosaki, I feel an odd sensation. Is it normal to react this way to you manipulations to my chest?"
He remained silent as he took a firmer hold of her and traced wet circles with is tongue around her nipples. Nemu started panting and began moaning softly. This new sensation was one she never expected to receive. She expected the male to enter some sort of metamorphosis caused by his interaction with a female's chest. This, however, was an entirely different thing.
It was like nothing she had ever felt before. It stirred her emotions. In most cases, she chose to retract her emotions from the situation since this would better aid Master Kurotsuchi in his research. This . . . this . . . felt good and she wanted to find out more.
Nemu crawled forward, over Ichigo's body, and placed herself directly over Ichigo's erection. Ichigo, on the other hand, was now between her legs getting an eyeful. "I have also seen that the women lick, suck and stroke the male sexual organ. A blowjob,as your people call it." She proceeded to expose his penis from under his boxers. "May I?"
But even before Ichigo could respond, Nemu took him entirely into her mouth. Every centimeter of his manhood was in her mouth, and parts of it, were down her throat. She did not flinch, gag, or react in any way. Ichigo couldn't help but roll his eyes in ecstasy. Every nerve in his body was on fire. Nemu slowly receded from him but then quickly picked up her pace.
Ichigo could feel every action she took. She began by sucking his entire erection in a very fast tempo. She then slowed down and focused on the head as she stroked the shaft in perfect synchronization. Next, she played with the soft underside of the head as she stroked and twisted her wrist along the entire length of him.
Ichigo could feel his climax nearing. He opened his eyes finally and a wet shadow in her panties. Ichigo took this opportunity to move them to the side and softly rub her clitoris. Shocks went throughout Nemu's body from his touch. Her breathing increased and the pleasure began to multiply tenfold. Ichigo easily glided a finger into her and began to entertain himself. Nemu could barely keep up with him as they both were at the edge of their desires.
"Mr. . . Mr. Kurosaki. I feel something inside of me. Like, like something is being stirred up. I don't know but it's . . . it's . . . it's—" but in mid sentence, Ichigo reached the pinnacle of pleasure and unloaded all over Nemu's face and chest. From this sight, Nemu, too, climaxed. She felt her insides convulsing, contracting and relaxing very quickly. She held her breath trying to contain a scream.
After a few seconds, Ichigo was able to breathe normally again. He felt fabulous. He felt a combination of excitement and released tension. He rested his head on the floor to relax, but the he felt a tug on his manhood. He quickly opened his eyes and looked over him. The sight was unbelievable.
Nemu was on facing away from him, on her knees, while resting her head on the floor looking back at him. "I have also heard of this thing called anal intercourse." With a somewhat red face, she smile and said, "Will you try that with me?"
Ichigo swallowed audibly. This was something VERY iffy, even with him. He usually considered such an action rather beastly. He stared at her face; it showed curiosity, joy, desire, and adventure. He then looked over at her waiting behind. It was ready and there for his enjoyment. But the thing that really convinced him was his own male side. It spoke clearly to him in his head, "This is one opportunity you DO NOT want to miss out on!"
He picked himself up off the ground, took off his boxers and dashed forward. This gave Nemu the cue to apply a lubricant she kept in the lab. Simple deduction told her that there wouldn't be any naturally lubricants available on a persons' body in that area, so artificial means were necessary. She handed the bottle and a condom to Ichigo and said, "Place some lubricant all over and then enter when you're ready." He did as instructed and then proceeded to attempt to do the task at hand.
He positioned himself behind her, making sure he had the right angle. He took hold of her hips and pushed himself slowly into her. Nemu instantly felt him. She felt herself widen more and more. She scratched the floor at the mild discomfort but, somewhere inside of her, she also felt her lust skyrocket. This combination was surreal to her. When Ichigo had inserted his finger into her earlier, she felt waves of pleasure. But this . . . this was on another scale altogether. She noticed that the further he pushed into her, the more the pain got trumped by desire.
Once he was fully inside her, Ichigo could have sworn that he came again, but just a little. The sensation was one he didn't expect. It almost felt like normal but there was much more added pressure and firmness around his member. It was a much tighter area which could only have the effect of a higher, more pleasurable sensation.
Nemu finally released her breath. She looked back at Ichigo and could see the excitement in his eyes. Ichigo also saw the yearning in hers. It was a look he never wanted to forget. Better yet, he wanted to increase it so he began to move in and out of her cautiously.
The moans and groans from both of them began to fill the room. They were both experiencing something exceptionally new and mildly devious. They were reaching an entirely new high and it was one that they welcomed happily. Both could feel the familiar sensation of orgasm rise from the pit of their stomachs.
Ichigo reached around and grabbed Nemu's breasts. He pulled her up into a near sitting position against his lap. He continued to thrust into her as Nemu arched her back, giving Ichigo a good angle to her opening.
"Nemu, I'm . . . I'm going to come again."
She couldn't respond. The sensation of her orgasm was extremely close and she wanted to feel every ounce of it that time. Ichigo moved slightly forward and bit down on Nemu's shoulder as he ejaculated. This final action brought her over the edge and she too climaxed.
Ichigo withdrew from her carefully, and lay back on the floor catching his breath. He was still trying to understand everything that had just happened. He wasn't sure if he should run since Kurotsuchi would probably find out what he'd been doing with his "daughter," and then have him probed for it. He figured the scientist would pull him apart piece by piece, and take out every one of his organs one by one. He thought the worst until Nemu came to him and leaned against his chest.
"Thank you for letting me investigate you and your body, Mr. Kurosaki."
Ichigo smiled to himself and figured—perhaps it was going to be worth being probed.
A/N: CONGRATULATIONS! Nemu let Ichigo experiment a bit on her, just as long as she got to experiment on him! Not a bad ending huh? Now, if you want to try for someone else - go back to the beginning and try again.