The legitimate son of the Gan family refused to study.
So Mr. Zhang sent Yan Xueshen to rescue him.
Then the son of the Gan family and the son of the Yan family got together.
Gan's father: I probably gave birth to a fake son. Mr. Zhang, don't leave after school. Let's talk.
(The reason why the setting was chosen during the Wei, Jin, Southern and Northern Dynasties is because men's fashion was more prosperous during the Wei and Jin Dynasties. "Book of Jin·Five Elements" records this: "Since Xianning and Taikang, male pampering has become more popular, even more so than female lust. All scholar-bureaucrats uphold it, and everyone in the world imitates it." So there will be no abuse from society or parents, and although it is a serious drama, there is no abuse at all.)