Sorry, Han glyphs render the same in Chinese and Japanese.
Regarding simplified versus traditional, no one is seriously unifying those.
There's some minor disagreements as to when a minor stylistic or historical variant deserves a separate glyph, but this isn't about rendering different glyphs in Chinese or Japanese. If Unicode is doing its job no one should have difficulty reading unified Han characters in one font regardless of language.
Regarding simplified versus traditional, no one is seriously unifying those.
There's some minor disagreements as to when a minor stylistic or historical variant deserves a separate glyph, but this isn't about rendering different glyphs in Chinese or Japanese. If Unicode is doing its job no one should have difficulty reading unified Han characters in one font regardless of language.