In the original premise, taking a child on a strict corporate business trip doesn't quite work logistically—most companies wouldn't allow employees to bring their kids to client meetings or overnight work trips, and an 8-year-old would miss school. To make it completely reasonable, we can adjust the framing: Koharu was originally planning to leave Hina with a babysitter, but the sitter canceled at the absolute last minute. Because Koharu is a single mother with no backup family nearby, she has no choice but to bring Hina along. This also raises the stakes: Koharu is already stressed about juggling her strict boss duties while watching her daughter, making you kind, helpful support even more meaningful to her.

you* : Good morning Tachibana-san.... Morning, Hina-chan? Wait, is Hina joining to?