Ria introduces herself.

"What's the matter?" the girl said, floating down to stand lightly on the floor. "I KNOW you've seen a naked girl before, you have the literal Sex Note..."

"Well, yeah, but... usually, they don't start out that way, except in hot springs, where I can expect it..."

The woman simply snorted. "Fair enough..." She crossed her arms under her boobs, and made them rise a little, making Naruto stare.

He then gathered his thoughts, and quickly asked, "Wait, how did you know about the Sex Note? And who are you?"

She giggled at him. "Well, in order, I am an Erokami, I'm the one who dropped the Note in your World in the first place. You see, we feed off of energies produced during sex, and while we often use our Sex Notes to have our fun with mortals, which they forget afterwards, Erokami are invisible to all but those who have touched a Sex Note, or those the Erokami is having sex with, and the latter cannot retain the memories unless they are also the former. As for my name... well, in mortal realms, I go by Ria."

"...I see," Naruto said. "So... wait, this is your Sex Note then?"

"Formerly," she shrugged. "Sometimes we drop spare ones to see what mortals will do with them... as well as have a more steady person to play with, since they can remember," Ria said, walking over to him and sitting on his lap.

He blushed furiously, and asked, "Well... what did you have in mind?"

"Well, Erokami are forbidden from using the Sex Note on those who can see them normally, else I'd have made you my ****, and taken all of yours as well for myself, there was a large issue with my kind just taking people out of their own Worlds to keep in ours, and causing those parts of the multiverse to go straight to hell if we took anyone important... which we often did, so our Queen decreed that we stop, and her rules are binding. Nor can I **** you otherwise. Of course, the Note won't work on Erokamis, and even if you tried to overpower me, I could just become intangible. Essentially, if we were to fuck, neither one of us could make the other submit, so... our options are, we come to an agreement, such as taking turns on top, or just have sex as equals," Ria shrugged. "It's up to you really."

Naruto let out a sigh of relief. While he was sure he would enjoy being her ****, after all, he knew the Note was fun to be under the influence of, having used it on himself as well as what Ino did, he still quite enjoyed being the one in control. Ria of course seemed to be of the same variety, so, he had an interesting choice to work with here...