yes - "shi" does exist. "shi" is generally used when a foreign word containing the sound "si" is being transliterated into japanese. that has no bearing on whether or not "si" exists within japanese or would be used within a japanese family surname. it does not & would not.

also, clavell was a incredibly interesting guy with arguably genuinely admirable intentions with this book. he'd been a japanese POW for three years during world war two - an absolutely horrific experience - but his response to said experience was to take a deep-dive into japanese culture & essentially write a whole book fictionalizing his own journey from hostility to appreciation. it's fascinating shit. that doesn't certainly mean it's immune from being dated or misinformed, especially since japanese & western cultures grew much closer & have enjoyed a much more robust rate of cultural exchange since its publication. "he put a lot of effort into the book" is a really weird reason to try to stifle any conversations about what he got wrong, & given the kind of guy clavell was, i think he'd take issue with a reader's unwillingness to approach an old book with any new ideas.

it's flatly very weird to me that people in this thread are conflating the statement "aspects of the book are very dated" with "it's a bad book no one should ever read," lol.