In the Spring and Autumn Period, Boya was good at playing the piano, while Zhong Ziqi was good at listening to the piano. Once, when Boya played the piano, the sound of the piano was like a mountain running water, and only Zhong Ziqi could understand its meaning. Later, people used "high mountains and flowing water" as a metaphor for bosom friends or confidants.

Ning Guan and Huaxin.

Guan Ning and Hua Xin live together, because Hua Xin loves money and doesn't concentrate on his studies, which has aroused Guan Ning's antipathy. Guan Ning cut off the mat and sat apart from Hua Xin, saying, "You are no longer my friend."

3. Lian Po and Lin Xiangru

Lian Po felt that he had made great contributions, but he was unconvinced by Lin Xiangru's comparison. Later, I learned that Lin Xiangfa took off his clothes with Vitex negundo for the country. Later, they finally became friends who vowed to live and die together.

4. Fan Zhongyan and Wang Zhi

Fan Zhongyan in the Northern Song Dynasty angered the imperial court by advocating reform. Before being demoted, all his friends avoided him, except an official named Wang Zhi, who went to see him off despite his illness. For Fan Zhongyan, such a true friend is valuable.

5. Zuo He

During the Warring States Period, Zuo He went to the State of Chu for an audience. On the way, it was cold and there was no food. In order to help his friend, Zuo gave all his clothes and food. He hid in an empty tree and committed suicide. Later generations called this intimate friend with profound friendship "Zuo Yang".