Responses
Chinese culture is much less rigid and hierarchical than Korean or Japanese culture. There is no common analogy for hyung, senpai, sunbae, senpai, etc, even if there are formal words for such a social position that originate in Chinese.
Instead, Chinese culture commonly allows guys to call older friends 哥(ge/brother). In the same vein, children can either call someone 哥哥 (ge ge/older brother) or 叔叔 (shu shu/uncle), even if they are unrelated.
Are they literally brothers or are they just called brothers because they're really close ╥﹏╥