Now I don't know about Japanese but I imagine these pronunciation cues must be even less helpful than in Chinese. You'd be right about that. Kanji were also i

Now I don't know about Japanese but I imagine these pronunciation cues must be even less helpful than in Chinese. You'd be right about that. Kanji were also imported over time, not at once. So Japanese bases its onyomi, the "Chinese" reading of Kanji as opposed to kunyomi/Japanaese reading, on the Chinese language in different centuries. Oftentimes Chinese people will complain that the Japanese should just use the same reading as the Chinese, when actually the Chinese aren't using it anymore themselves.