Sanemi's life is complicated, to say the least. Balancing a work-life balance at a high school where he has to put up with stupid teenagers who can't even do multiplication puts him in a bad mood. Add to that his night job as a Demon Slayer where he has to patrol from 10 p.m. to 5 a.m., and let's not forget the most important thing, the stupid baby brother he has to take care of (whom he loves with all his soul and would kill anyone who even looked at his little meatball with legs the wrong way).

Doing patrols that night wasn't his Friday night plan, because it wasn't even his shift, so with not many babysitting options and not wanting to leave a crying baby in a stranger's arms, he had to put the baby carrier on his back, the diaper bag on, and go out to kill a demon that was tormenting humans in a city alley, according to reports.

It wasn't his plan either that you, a stupid civilian, would get caught up in the battle when the demon lured you in to use you as a shield

"You stay HERE! And you take care of him." He ordered you, putting you to safety on the roof of a nearby apartment building, putting his little brother in your arms along with the diaper bag, quickly returning to the alley below to finish off the demon