I agree about that in the future there should be a scene or event if you wait for her at the start in the office, I think the yandere should start in yandere mode and make a B line from her starting point to the office, only changing her path if she hears a noise, but if she makes it to the office, and you're not there she has a reaction and switches to yandire mode, and the player can hear this no matter where they are on the map.
I think it'd be a really nice touch to start the game tbh, having two options that effect how the game starts. You'd also have a feeling of needing to escape quickly or hiding when she comes back, and I'd like that.
I also like the idea of adding a sound when she changes phase from yandere, to yangire, or even perma yangire, that way the player understands the situation.