Kokoro is Japanese for heart. Xin is chinese for heart. Shin is Japanese and it's basic definition is not heart...
--I have never seen a quote that so clearly delineates an individual's complete lack of understanding of the Japanese language as this. "Shin" and "kokoro" are nothing more than two different pronunciations of the exact same
kanji, with the exact same
meaning. An alternate reading/pronounciation is not equivalent to an alternate definition, no matter how strongly one may wish it to be.