>>724579651
>>724579189
According to what I know, and take it with a grain of salt...
>San
This is unisex, a term of respect like "mr." or "ms.", the term a teacher would typically use the first time she refers to a student, can't go wrong with it
>Kun
A less formal honorific that is mainly masculine*, used between friends and people on the same status or age/grade/ranking
>Chan
The same as the above, but feminine*
*Japanese doesn't actually have gendered pronouns or honorifics, they simply evoke the feel of masculinity or femininity, so calling a masculine woman "kun" or a feminine man "chan" is not incorrect, but usually people won't do this out of politeness
TLDR what the teacher said wouldn't be incorrect if the student was male, female, or even if they were "neither" it would still be totally acceptable
No clue what that page is meant to express then