Once Black Sperm finally got into the rhythm of things time just seemed to fly by. Days became weeks and weeks became months, and every day had a similar theme to it.
That is, a standard cycle for most days would consist of spending time either eating, sitting around doing nothing, playing with Fubuki while Tatsumaki is at school, playing with Tatsumaki, or playing with both of then. Time passed by just like that every day.
Surprisingly but not entirely unexpectedly, he and Fubuki were practically Tatsumaki's only friends. Occasionally Tatsumaki would divulge her less then stellar school interactions with other kids to him when she felt like it, and Black Sperm as her dutiful underling would give various reasons as to why the other kids were huge assholes.
It wasn't really active attempts at scheming to isolate Tatsumaki so much as him giving his two cents in and letting things take its course. It was the humans themselves that worked to isolate their own after all, especially those different and out of place like Tatsumaki here.
Of course Black Sperm could really care less if Tatsumaki had friends or not. He was just around for the food and protection. It wasn't much of a cause for concern to Black Sperm if Tatsumaki became distracted by other worldly things, and if those things decreased the workload for him of having to put up with the antics of two little girls then so be it. He was just the family's exotic pet after all, it was better to be in the background sometimes quietly returning to be.
Fubuki became a bit more verbally coherent at least, or maybe she just squealed less. And he got a respectable seven hundred and twenty three (723) more cells to his stock in food so far, twenty three were of them sent off to scavenge the wild for more food and to scout around just in case. Life was looking good so far...
But one perfectly normal day there was something really interesting that happened. Some guys in suits and lab coats came around with a van and some expensive looking machinery, what it did was beyond him, it looked like an electric chair at first glance but that obviously wasn't what it was.
Black Sperm looked from the window how they hooked up the two sisters to it one after another and seemed excited while Tatsumaki was on.
Black Sperm didn't think much of the event until a few hours later when he saw Tatsumaki leaning her head on a hallway door with a focused expression, as if listening to someone.
"Eavesdropping?" He asked, slightly curious.
Tatsumaki put a finger on her mouth as a sign to shush him. Black Sperm promptly leaned on the door to hear what was going on the other side with her.
"How much for her? 22,706,600 Yen?! Well I don't know if I can say no to that. We could be set for quite awhile with that!"
'Oh...OH! Well isn't that something! The kids parents are selling their daughter off to a bunch of white coats.'
Black Sperm having heard this quickly looked to the side see Tatsumaki face scrunched up in be unrestrained horror and betrayal, then after that sorrow.
"M-mama and papa are selling me?" She started tearing up.
Black Sperm stared at the the little girl who collapsed on her knees sobbing. He probably would've been laughing in her face had she not saved his ass that one time and continued to feed him after. He still thought it was kind of funny to see her witness humanity's worst. Humans being as shitty as Mysterious Beings wasn't a surprise honestly. What he didn't like was how it jeopardized his main source of protection, particularly her mental state.
'No friends because of her powers, and her powers are the reason her parents are selling her to some scientists. Wow! What shitty luck you have Tatsumaki!'
Considering how she defended against that one monster awhile back Black Sperm had a small feeling whatever facility the lab guys had in mind wouldn't be able to contain her for long if she developed a mind of her own. Perhaps this situation could be spun in his favor somehow?
Seeing this as an opportunity to further cement himself into Tatsumaki's life and gather information on the outside world, Black Sperm had an interesting idea.
"Hey kid. Wanna see something?"
"Wha?" Tatsumaki looked up, her eyes and face filled with tears.
Without an ounce of effort Black Sperm divided into two. In front of Tatsumaki stood two of himself.
"Th-there's two of you! Did... did you have a baby?" Tatsumaki asked with wide eyes.
"The hell?!"
"What? No!" Both Black Sperm's shook their heads in denial, before explaining what he just did.
"That's my power you see. I can split into more copies of myself, I'm me but he's also me." Black Sperm explained.
"W-woah. That's so cool!" Tatsumaki sniffed and rubbed one of her eyes.
"So as you can see. I can split to stay here to keep your sister Fubuki company." One Black Sperm began.
"And also come with you at the same time so you're not all by yourself. It's pretty simple and convenient really." The other Black Sperm ended.
"R-really?! You'll do that for me?" She asked in disbelief.
"Yeah. If you're being sold off I might as well come with. You're still the boss, and you're not gonna get rid of me that easily. Oomf!" Black Sperm felt Tatsumaki wrap around him in an embrace. Her wet face rubbing into his shoulder releasing more tears.
'Tch! Now you're getting me wet with your girl fluids. Useless child who can't stand up for yourself... why do I need to be on the receiving end of your wet affection?'
Black Sperm felt like pushed her off for using him as a tissue rag, but felt it might not be strategically advisable. She technically could kill him with a thought, so he relented and allowed the display of affection to continue.
Both Black Sperms stared at each other knowingly. The one holding onto Tatsumaki signaled for his other self to go off to Fubuki.
...
One cell group of three hundred Black Sperm sat in the back of the van while Tatsumaki rested on his shoulder. He wasn't sure what to expect from the facility that they were being taken to, but the fact that it was an armored vehicle they were inside didn't make a good first impression.
At least it didn't take much convincing to have himself be brought along this traumatic field trip either. As one of Tatsumaki's conditions for cooperation was Black Sperm's presence, who the scientists upon seeing some of his unique abilities accepted.
Though, Black Sperm decided to keep hidden the sheer extent of how much he could split and shape shift. And they ended up concluding him to be of little use. Black Sperm fucking hated being considered a useless tag along, but some things one just had to put up with when you wanted something more.
Not that it would've mattered to hide it, Tatsumaki was the special one the lab guys ended up focusing on with various tests and analysis, and Black Sperm was once again left to his isolation in a child's room for most of the day.
It was a rather cold facility dedicated to researching different phenomenon for the benefit of humanity. It wasn't very comfortable considering he was practically shackled to Tatsumaki here, but since the place provided free protein for free Black Sperm might as well have considered it another vacation home.
They provided toys, games, and magazines to Tatsumaki after tests. Black Sperm was pretty satisfied with lazing around messing with what new things she got. On the other hand it was a tad irritating to see his boss sobbing to herself at night, clinging onto him for dear life, like some sort of comfort plushie.
The weeks and months passed and Black Sperm got into a vaguely similar rhythm of eating to rebuild his cell count and spending time with Tatsumaki. The food wasn't very good if Black Sperm was being honest, and Tatsumaki's depressed mood dropping down even lower every so often wasn't a good sign for her stability. He only cared about her so much as it helped him, and it seemed that Tatsumaki could perhaps use some encouragement.
"Hey Tatsumaki. You holding up well?" Black Sperm asked, trying not to sound as disinterested as he really was.
Tatsumaki shook her head and closed her eyes in a sigh, and like many days she threw herself onto Black Sperm into a cuddle. Her only source of comfort as her beloved sister Fubuki had been left behind, and her parents had essentially abandoned her.
"I wanna go home. I miss my sister." She said sadly.
Black Sperm hummed. Trying to sound like he cared. Maybe he cared like a little bit, Tatsumaki's depressing vibes were starting to rub off on him.
'Maybe when I eat and get protein I'll break us out.' Black Sperm considered.
"Um Black?"
"What is it?"
"Where did you live... before we met and I took you in?" Tatsumaki asked.
"Didn't live anywhere." Black Sperm said.
"Oh. So you were all alone out there?"
"Alone? You saw my powers right? How I could I ever be alone when I have myself?"
"O-oh yeah that's right. You'd be kinda like your own family then." Tatsumaki said.
"In a manner of speaking yes."
"Did you ever have a mama?"
"No. Never had one and never needed one. I wasn't born like a human."
"But I thought everyone comes from... mamas? How did-
"You sure are asking a lot of questions missy. I think you need to rest some." Black Sperm cut her off.
"... Okay."
'God. Dealing with an emotional needy brat is a pain in the ass. I wonder how other me is doing.' Black Sperm thought.