Quite well, though Mei makes things a little awkward!

Before Izuku could even question why this girl was on a pogo stick of all things, she had jumped off of it, right into All Might's arms. "It's so good to see you, Melissa!" he exclaimed, easily catching her in a hug, even with one of his hands holding Mei's bag of gadgets.

"Oh my gosh, it's been forever!" Melissa agreed. "I'm so glad you're here!"

"I almost didn't recognize you," All Might agreed, holding her up like she was a toddler. "You've gotten so grown up!"

"Well, I am 21 now, you know!" she replied cheerfully. "Much heavier than the last time you saw me!" she joked.

As All Might denied such, Momo leaned in to whisper to Izuku, "And it's in all the right places..." He flushed a bit, but didn't argue with that. Melissa was smoking hot. He watched the two chatter for a moment, before All Might turned to the group.

"Everyone, this is Melissa Shield, the daughter of David Shield, and-" All Might suddenly started to say, before Mei squeed, and shot forward, right up in a bemused Melissa's personal space.

"You're THE David Shield's daughter? Are you an inventor too? What kind of babies are you working on!?" she asked, speaking extremely fast, and stepping forward whenever Melissa took a step back.

"B-babies?" Melissa stammered, wondering if she had misheard with how fast Mei was talking, or if her Japanese was rusty.

"She means "inventions,"" Izuku clarified, rubbing the back of his head. How he didn't see this coming, he didn't know. "That's extremely important to know when dealing with her, or you'll have WAY too many questions..."

"O-oh!" Melissa replied, adjusting her glasses, before she and Mei immediately started getting into a talk about things they invented, a lot of terms going over everyone's heads.

"...dear Lord, Young Midoriya... What have you done?" All Might asked with a sweat drop.

"I'm so sorry, All Might," Izuku wept comically as the two chattered.

After a few minutes, Melissa cut it short, flushing. "Oh, right, sorry everyone, started getting carried away there!" She chuckled nervously, rubbing the back of her head, her eyes closed.

Momo naturally found the gesture adorable. Why, why did her Master have to have such a long timeline by her standards? He'd only have a couple days here, not enough time for him to build the level of relationship he wanted before making a move on her...

All Might proceeded to introduce everyone to Melissa, before finishing it with, "Everyone here aside from Young Hatsume and Ms. Midoriya here are students in the Hero Course."

"Oh, that's interesting!" Melissa noted, before she suddenly started looking everyone's costumes over, muttering to herself about potential improvements.