It all starts the night after the revelation. You see, Kisuke is a scientist through and through. Which means that he loves the thrill of discovery, yes. But it also means he knows the importance of accurately preparing for an experiment so that it doesn't blow in your face. Not without the appropriate precautions anyway. And yes, Kisuke also knows that he mostly ignores all of that but in this particular case, he'd rather take care of his kids.
Which is why the next science binge is no science binge at all but a week-long study session. Kisuke devours every single piece of information about parenting he can get his hands on. The fourth's library will never be the same. Urahara is not sorry in the least. And yes, Kisuke learns to change diapers too because have you met his kids? Trouble followed them everywhere and most of the time it made no sense.
It's Kisuke being ready, just in case! Yoruichi, stop laughing! If this skill is ever needed, Kisuke's not teaching her how to do this right. She can suffer on her own. He feels smug for about a second until Yoruichi tells him he might need it more when his kids get kids on their own.
Cue more panic and another week-long study session. Grandfathering can't be the same as parenting after all but there is no information about it anywhere and how is that even possible? He even consults Kotetsu because this is obviously a terrible oversight. She doesn't seem to understand the problem, no matter how hard Kisuke tries to explain.
It takes a while but eventually even the fourth's patience runs out and Kisuke finds himself back in his little shop. And he comes back to find two more kids tentatively finding their footing in his household. They're like stray animals. They came one day when he wasn't looking and now they're trying to figure out just how welcome they are.
It begins with Keigo skittishly staying to one of the kids' study sessions, shyly sliding over to Urahara to ask his questions and looking so very relieved when Kisuke proceeds to answer. Mizuiro is far more blatant. He just shows up one day with his phone over his face and just never left. Kisuke hasn't missed the new security surrounding his shop, either.
Apparently, Mizuiro is something of a yakuza boss. Kisuke thinks it's adorable.
After the boy finds a room made up for him, Kisuke finds some highly illegal but very interesting chemicals magically appearing on his lab and Mizuiro looks so relieved when all Kisuke says about it is to make sure he doesn't get caught. It's slightly cute.
Far be it from Kisuke to lecture others on the legality of their actions.
So during a breakfast, Orihime's turn but no one has the heart to deny her enthusiastic attempts at food making, Kisuke looks at the two teens and wonders. They're somewhat new to his shop but longtime friends of Ichigo. He sees the untouched potential and he thinks to himself: "I could have two more." It's not like he's lacking the space... Some of it must show on his face because Yoruichi snorts beside him.
It turns out to be one of the best choices he's ever made. Mizuiro somehow gets his hands on chemicals even Kisuke has a hard time finding and Keigo has a talent in making things explode almost without trying. It's beautiful. Kisuke's delighted and if the Soul Society isn't, well they know better than to say anything in the presence of his kids. And when they catch him on his own, Kisuke shows them his little notebook of observations and reminds them that this is science they're doing.
It all starts when Yoruichi informs him that Kukaku would like to have her cousin around every now and then. Which leads to the kids deciding that this, of course, is a group thing and Kisuke is somehow roped into all of this. He has no idea how it happens and when he realizes how well they manoeuvered him, he can't stop himself from beaming.
Manipulative little brats, he's so very proud.
That's how Kisuke finds himself observing as Kukaku tries to teach Ichigo the fine art of firework creation. It's a Shiba Clan thing, she insists. There's a glint in Keigo's eyes when he asks if he can join in. And Kisuke, well… He looks from the Clan Head to the fireworks and explosives and then to his kids. And back again.
Kisuke thinks he might have an idea.
Because all the books said that family activities are important things and well, isn't this just perfect?
Yoruichi looks at him for about two seconds and then disappears. Kukaku is offended only until Kisuke manages to drag her a little to the side and propose his idea. It's the start of a tradition. Kisuke takes his kids to the Shiba's every week so they can all explode things together. He gives them all notebooks to write their observations on because he has long lived by the belief that the only difference between willful chaos and science is writing it down. And fancy words, that too.
The first time that his kids show their notebooks in explanation after someone had the guts to ask them what they're doing during an experimental explosives testing day, Kisuke can't help his beaming. He ignores, of course, the sudden paling of the soul reapers around him. They just don't appreciate science. It's a shame, really.
And if Soul Society starts bending to Kisuke's whims once they learn that his kids are learning to explode things, well… Kisuke is not complaining.