inseparable friendship; deep bond
A classical Chinese-derived idiom referring to an extremely close, trusting friendship, like that between Guan Zhong and Bao Shuya. Used in literary or formal contexts.
It is said that there is an inseparable friendship between the two.
Another classical idiom for an inseparable relationship, often between a ruler and a wise minister.
From the Chinese historical story of Guan Zhong and Bao Shuya, whose friendship was so strong that they trusted each other implicitly despite political differences. The idiom is used in Japanese to describe an ideal, unbreakable friendship.