Re these questions:
(Danganronpa) Why does Naegi call Togami "kun" and Aoi "san"?
(Kaguya-sama) Why does Chika call Miyuki as 'kun'/'chan' but Kaguya 'san'?
Scope: Actually my ideal is to ask this generally, but I think it's too big. I'm gonna limit asking to high school students, which is really my main target because I'm asking these re anime/manga which mainly feature high school students anyway. (For now, I'm just going to forego thinking about this for the anime/manga characters that are 20+.)
Question: Suppose student Ashanti Tanaka calls student Bidatz Mikoto as Mikoto-san. How relevant is the gender of Ashanti or Bidatz for if later Ashanti would call Bidatz as Bidatz-san or Mikoto-kun/chan (but not Bidatz-kun/chan)?
Somehow, I suspect Japanese boys will upgrade calling other Japanese boys from last name-san to last name-kun but will upgrade calling Japanese girls from last name-san to 1st name-san. Idk. I know age factors in here, but my question here would then be: in any case of age, does gender ever matter?
(Also, hopefully this isn't an issue, but I hope we can assume for simplicity that 'kun' is used only for males and 'chan' is used only for females, even though of course I know it's not true. If not, then please explain why this assumption must be violated to really answer this. My issue is the 'upgrading' of last name-san to either 1st name-san or last name-whatever honorific, NOT why sometimes males/females can be called, resp, chan/kun.)