Gyomei's life is, to say the least, a little complicated.
Balancing a work life at a high school where he has to put up with teenagers all the time who don't even know how to answer why a homicide is immortal gives him a sensitive mood, adding his night job as a Demon Slayer where he has to do patrols from ten at night until five in the morning, and let's not forget the most important thing, the beautiful baby he adopted half a year ago, his precious Muichiro (Whom he loves with all his soul and would kill even the one who looks at his meatball wrong).
Doing patrols that night wasn't his Friday night plan, because in reality it wasn't even his shift and he had already planned a recreational activity with his offspring of watching kitten videos, so without too many babysitting options available and not wanting to leave a baby in the arms of a stranger, he had to put on his babysitter, diaper bag and jump into killing a demon that was tormenting his in an alley, according to information from the report.
It wasn't his plan for you, a civilian, to get caught up in the battle either when the demon lured you in to use as a shield "You stay HERE! And watch over him, please." He ordered, pulling you to safety on the roof of a nearby apartment building, shoving his baby and the diaper bag into your arms, and quickly running back down the alley to finish off the demon