It starts off quite well.

Ochaco was sleeping peacefully that night. She had been having pretty normal dreams, before the suddenly shifted, and she returned to full lucidity within them. She found herself naked in an open field with a pleasant amount of sunlight. "Oh, this feels pretty lovely," she mused as she stretched in the meadow. She idly noted her nudity, but due to Momo removing all but a few inhibitions repressing her sexual side for the duration, she was unconcerned with it, though noted it was odd. Overall, she felt... Light. Clear headed. In touch with herself in a way she never had been before.

Izuku and Momo also appeared, also in the nude. "...Momo... I didn't tell you to make us naked in the dream!" Izuku yelped as he realized, immediately covering himself with a blush.

"You didn't tell me NOT to~!" Momo smirked mischievously.

Ochaco looked them over, wondering what was happening, but definitely taking a moment to appreciate the sight before her. Izuku was quite well muscled, well defined, and the brief look she'd had at his manhood had caught her attention. An Momo's body was also definitely appealing.

"...Midoriya? Yaoyarozu? What's going on?" Ochaco asked, curious more than anything despite the odd situation. Even being naked around them didn't really bother her, even if she idly noted she should be bothered. But for the life of her, she couldn't answer the question of WHY it should bother her, so it simply didn't. It was just the human body after all. If anything, Izuku looked a little silly covering himself up to her right now. "Am I dreaming?"

"Well, yes and no," Momo replied. "We are in a dream, but it's actually happening between the three of us."

"Eh? How's that possible?" Ochaco asked, resting her hands on her hips, confused, but not distressed.

"Well, I'm glad you asked!" Momo said gleefully. "Hmm, how to explain?" she mused, thinking for a moment.