XML source code difference for Japanese texts in English and Japanese Contexts

Question

For Office Excel with edit and proofreading language in English, add below yellow frame highlighted Japanese texts and save, then open XML source code, it keeps in below red frame highlighted contents, this is what we are expected

For Office Excel with edit and proofreading language as Japanese, add below yellow frame highlighted Japanese texts and save, then open XML source code, it changes in below red frame highlighted contents

Compared with previous English version, redundant Font html Color and Family attributes are added, we are wondering why such change happens ? And how to achieve the same English source code format in Japanese language ?

Thanks so much

Image

BRs

Pitt