He's working hard so that more of the family's money could be spent on the younger siblings, giving them a better quality of life. My assumption is that it was You checking on Asuka, not Asuka complaining to You about Kei failing to appear.
@plsnobully It's a sign of a good series if you can't always guess what's going to be happen next.
Gotta be honest Jeibmade a huge mistake there... Even if there was no romance leaving a girl alone like that in such a huge festival during night is a risky move...