In ancient China, there was a word "senior", which refers to the person who presided over the study affairs. In the book "Random Talk on Gaizhai" written in the Song Dynasty, it is written: "Zhang Jian is the great responsibility and Zhang is the deputy." The word "modern senior" mainly comes from the senior system promoted by Kang Youwei. At the end of the Qing Dynasty, Kang Youwei founded Wanmu Caotang, absorbing and drawing lessons from the student management methods of the new school at that time. In order to give full play to students' subjective initiative and let students manage themselves, the senior system was implemented in Wanmu Caotang, and excellent students were hired as seniors to guide students and manage all the work in a division of labor. Usually, the senior is responsible for assisting Kang Youwei to manage and maintain the learning and living order of the 10,000-mu thatched cottage. When Kang Youwei is out, the seniors are responsible for giving lectures and correcting students' exercise books. Therefore, as soon as Kang Youwei went out, all teaching activities went on as usual. During the Republic of China, the senior system evolved into a spirit of equality and friendship to guide and help junior students and realize benign interaction and communication. The senior system has also changed from junior to senior, and it is still practiced in China, Taiwan Province Province, Hongkong and Macau.
As mentioned above, most people in Chinese mainland are not very clear about the origin of the word "senior", and they always think that it is quoted from Japanese, which is also quoted in Taiwan Province Province and South Korea. But in fact, both in Japan and South Korea, junior students are honorifics for senior students (Japanese ancestor: せんぱぃぃぃぃぃぃぃぃぃぃ𞊣𞊣𞊣) It means that the word senior has nothing to do with Japan and South Korea because they don't use it at all. To quote, ancestors in Japanese and Korean do have a referential relationship.
There is also the word "senior" in Japanese, but it refers to the president of a university (the senior takes office/takes office as the president of a university), which is far from that of China.