I don't know manga chapters but this is from the novel.
I think it was a few chp before the ending I don't know to remember for sure. but I do remember the part where the emperor had to dismiss the harem and stay chaste for some time before the empress finally relented but only by a bit. the emperor almost went crazy.
Spoiler alert
He fucking raped her. I fucking hate this. When someone doesn't move during sex(rape) they're usually blocking it out and hoping it ends faster. Why the fuck didn't y'all say there was rape please I am literally sobbing. I felt so uncomfortable land started crying. If the manga goes the same route I'm dropping it.
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She is just disgusted by the emperor.
In the later parts when even when they fall in love she just staright up.vomits on the emperor when they try to have sex because she thought about the emperor as a male prostitute who has been touching too many women and the thought of him touching her makes her vomit as a reflex.
This whole novel is gold.