That's a spin on the usual "saving the falling girl" trope. Did Izumi accidentally bump the stepping stool right before Honami fell, which is why she fell sideways and farther than she was supposed to? Well, I'm just surprised they didn't go with the ecchi staple trope of the physics defying panties-to-face fall...
And I think she actually injured herself this time. That ankle's gonna hurt for some chapters after this, at least next chapter for sure. Maybe she'll even come in with a crutch or something, and that will give him a reason to assist her even more. Taking responsibility and all that.
Indecent? Right, beneath that innocent looking face is a girl with a dirty mind. Not saying that's a bad thing. But I do like how Izumi straight up asked her if she wanted to see something indecent before she went into denial...
Shiyu is so powerful she isn't allowed to disturb the peace every chapter after her introduction.