Traveling Through the Tang Dynasty, I Am Doing Business in the Harem

After the protagonist traveled through time, he was assigned to the harem as a "handyman" in the harem, and found that the three thousand beauties in the harem each had their own concerns - the emperor was busy with government affairs and had no time to favor her, the concubines were intrigued by each other, some wanted to be in power and others wanted to save their lives. The protagonist's "business" is actually: