Here's why:
* "Hai" is not a direct translation of "yes" in either language. While it's used to express agreement in both Japanese and Chinese, the nuance and context of its usage can differ.
* In Chinese, "hǎi" (海) means "sea". It is not used to express agreement.
* In Japanese, "hai" (はい) is a polite and respectful way to express agreement. It is often used in formal situations or when addressing someone older or of higher social status.
* Chinese uses different words to express agreement, such as "shì" (是) or "hǎo" (好). These words are more direct equivalents of "yes" in English.
The confusion might stem from the similar pronunciation of the Japanese "hai" and the Chinese "hǎi". However, they are distinct words with completely different meanings and usage.