Also remember, we are not talking about a Star Trek based on modern Japanese sensibilities but those of Imperial Japan.
The "Federation" of the 26th century would be a "global co-prosperity sphere" dominated by Japan and reflective of Japanese sensibilities. There might be a multiracial crew, but all positions of real authority would be held by Japanese people - with the possibility that one or two Europeans or Anglo-Americans might be along, taking the role of freindly "space aliens" like Spock. Women crew would be limited to traditional female roles (nurses, clerks, etc). The Global co-posperity sphere's goal would be expansion to benefit Earth.
So, HIMS Yamato's role would be to go "where no man has gone before" to contact alien worlds and try to bring them into the Co-prosperity Sphere, preferably by peaceful means and trade relationships, but there would always be the threat of military force. There would be no sexual attraction between humans and aliens, period, and virtually no sexual element to the show at all.
The main "bad guys" would be other alien species who are attempting to expand or keep their empires over the same aliens the Co-Prosperity Sphere wants to "help". Perhaps one set of enemies would be an old empire resisting independence movements (think Europeans) and another set which is actively expanding into areas the Co-prosperity Sphere has already absorbed (think the USA or USSR). The appearance of the bad aliens would represent accentuated White or African traits, possibly on the same individuals.