Newt isn't great with kids.
It's not like Newt needs to be great with kids, since he studies kaiju, not pediatrics, but his extended family seems to think it's some kind of failing, so he hears a lot that he's not great with kids when he isn't hearing that he should take a safe university job somewhere on the Atlantic Ocean.
So, when Marshal Pentecost acquires a kid from somewhere (nobody asks Pentecost a lot of questions lately, even if Newt has a lot, like “What was it like to pilot a Jaeger solo?” and “Hey, do you think you could requisition me a kaiju heart?”), Newt doesn't pay too much attention to her. The marshal talks to her in slow, determined Japanese, and she answers back in accented English, and he's pretty sure it would be adorable if anyone dared to all Stacker Pentecost adorable.
So, given that, Newt isn’t sure what makes him open his mouth when the kaiju alarm goes off one afternoon when the kid (nobody is really sure if she's his daughter or his co-pilot-in-training or his shadow or a mass hallucination, and nobody is asking but everybody is taking bets) is following Marshal Pentecost around and Newt and Hermann are trying to give him a report. But Pentecost looks stressed and the kid is the kind of still that probably means she’s terrified, so Newt blurts “Hey, kid, want to watch me dissect a kaiju tendon? It's fresh!”
There’s a pause in the chaos of the Shatterdome while all of them consider what a completely terrible idea that is, while tech crew goes around barking about prepping the Rangers on call for battle.
To Newt’s surprise, Hermann is the one who answers, frowning and bending to meet the kid’s eyes even though Newt is pretty sure bending is not great for Hermann’s anything (and Newt isn’t even that kind of doctor, he should work on that, mental note for when the world stops ending). “Do you want to come, Mako? The lab is safe.”
She looks up at Pentecost, who glares between them like he’s just barely resisting telling them exactly where they can put their offer, so Newt is kind of surprised when he eventually gives a grudging nod. “All three of you stay in the lab,” he says, and Newt needs to really work on the being forbidding thing, he is hopelessly outclassed here.
The kid nods solemnly and lets him push her towards them. “We’ll take care of her,” says Newt, and smiles down. “Come on, little Pentecost, we’ll get you in a lab coat, that’s what makes it science.”
"Mori," she says, surprisingly strong. "Not Pentecost, Mori."
"Okay, little Mori, we can go with that. Hey, you ever learn German?" Newt keeps up the chatter as they trot to the lab (well, trot slowly, she has little kid legs and Newt may not like Hermann that much but he’s not going to leave him in the dust, that is not his brand of asshole). The kid gets in maybe one word to every twenty of his, but that’s okay, she looks a little less terrified.
She perches quietly in a chair when they get to the lab. Hermann paces while he does his equations and frowns and doesn’t lean enough on his cane. Newt mostly forgets about little Mori while he narrates his dissection out loud until he catches her staring at his rolled-up sleeves and the tattoos underneath. He grins at her. “Like my collection?”
"Yes," she says after an amount of deliberation that’s pretty hilarious for a kid who can’t be much older than twelve.
"You can get some of your own someday!” Newt reconsiders. “Definitely not today, don’t tell the Marshal I encouraged you to get tattoos, I am pretty sure he would toss me out in the next kaiju attack, tattoos are really permanent and you should think about them. If you want cool colors, you could always dye your hair."
"Dr. Geiszler," Hermann says in his very special pissy way, and then turns to the kid. "Mako, would you like to see some proper science? You must be old enough to be learning what the scientific method is."
Newt loses the kid’s attention after that, but he isn’t paying much attention to her either, so he can’t say he minds, even if he’s pretty sure that no matter how bad he is with kids Hermann should be worse. By the time Pentecost comes back, two hours later, she’s sitting at Hermann’s desk working on statistical equations and Hermann and Newt have probably argued less in those two hours than they have since they met in person.
Little Mori very politely shakes Hermann's hand, and then Newt's. “Thank you for inviting me.”
Pentecost gives them a suspicious look like maybe they've been corrupting her (sometime in hour two, Hermann got it out of her that Pentecost adopted her after she lost her parents in Tokyo, so he kind of gets why he's so protective of her), but Newt ignores him and crouches down a little closer to her level. “Hey, little Mori, it was a pleasure, and you can come back any time.” He looks up at Hermann. “Right?”
For once, Hermann doesn't argue first, probably because the kid already has him wrapped around her finger. “You're welcome whenever we aren't doing delicate experiments,” he says, which is as close as he ever gets to warm and welcoming.
Pentecost softens just a little, looking at her, and puts his hand on her shoulder, somehow managing to look scary even when she leans against him. “We'll see what we can arrange,” he says, and ushers her away.
On the whole, Newt would say, probably a success, and he waves at her when she turns to look over her shoulder on her way out.
(Two years later, Mako shows up to the lab for her practical science lesson with the tips of her hair dyed blue, smiling shyly, and while Hermann exclaims over how good she looks Newt thinks maybe he's not so bad with kids after all.)