I tried right from the start, a clause in the prompt - in this case (which is inherently not going to give what you are searching for in underlying name meanings): don’t copy the same Japanese person in every picture; give the “ko” portrait assignments uniqueness by underlying demographic usage by portrayable ethnotypes, etc.
Funny: Sakurako gets cherry blossoms, Yukiko gets snow, Ainuko: literally Ainu? etc. The model can’t help itself, like the “Bambi” or “Cherry” I showed before.