Re these questions:

 - https://japanese.stackexchange.com/questions/93904/how-does-last-name-kun-compare-to-1st-name-san

 - [(Danganronpa) Why does Naegi call Togami "kun" and Aoi "san"?][1]

**Scope**: Actually my ideal is to ask this generally, but, based on the above, I think the scope's too big and there's like a specific section in 1 answer about high school students specifically. So, I'm gonna limit to high school students, which is really my main target because I'm asking these re anime/manga I watch 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 25+.)

**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)?

- In this regard, I don't think Japanese customs are that different from Western customs here. I notice it's common for boys to be addressed by their last names while girls are addressed by their 1st names (at least with each other if not with the opposite gender?) but of course the degree of commonality is different. Wen Japanese boys call each other by last name-kun I think it's the same as when Western boys call each other by last name. When Japanese boys call Japanese girls last name-san, I don't think it has the same meaning when Western boys call Western girls by last name. 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.** If not, then please explain why this assumption must be violated to really answer this.)


  [1]: https://anime.stackexchange.com/questions/36915/why-does-naegi-call-togami-kun-and-aoi-san/40442#comment78780_40442