Domino Kick
Summary
Sae, a young lady of a wealthy family, sometimes can't control herself and gets the urge to behave in a manner unbefitting of her upbringing. It's her butler's job to intervene.
This is the original Niconico Seiga version of "Domino Kick - Naraberareta Domino o Kick Shitara Dou Naru no Kashira?" (I wonder what would happen if I kicked a line of dominoes). As opposed to the Gangan Online version, it doesn't have the subtitle and has a partially different set of chapters.
In a system like that there would need to be rigorous documentation and certificates of prior ownership/guardianship or else anyone and everyone would just get grabbed off the street and enslaved at any time, and such a society would collapse instantly. So these slavers wouldn't have such documentation unless it was a forgery since the kids were just kidnapped; both offenses should be very serious capitol crimes. Once again, the day is saved by glorious Bureaucracy! (and the MC's knowledge and exploitation there of).