Ever wondered why people in English-language conversation like to arbitrarily use “san” when referring to Japanese people? Me too. But now you can learn what “san” means in this excellent article on Tofugu by Michael Richey and Mami Suzuki.
Japanese names can be very gendered by social convention. But the origins of the name honorifics are not. For example, -chan (typically used for close female friends, and for upending someone’s masculinity) has nothing to do with being female:
There’s no etymology for the name ender ちゃん, but the popular consensus is that it evolved as a baby-talk version of さん. It makes sense. Whenever you have a widely-used word, kids in any country are going to mangle it with their baby mouths. Kids in Japan often have trouble pronouncing さしすせそ/たちつてと, and transmute it into しゃししゅしぇしょ/ちゃちちゅちぇちょ. Thus, さ became ちゃ, and suddenly we had a name ender to call kids, small things, and cute things.
And neither does -kun (typically used for male names for people you aren’t that close with):
As the Tokugawa Shogunate came to an end, rigid samurai classes all went out the window. At this time, 君 received a second reading, くん, which is a name ender used to pay respect to anyone and everyone without acknowledging any kind of complicated, samurai-style hierarchy. The chairman of the Diet of Japan began using 君 with Diet members, and the tradition continues to this day.
And for the record, Keio University also calls everyone (save for the founder, Fukuzawa Yukichi) –kun:
The school was originally a one-sensei operation founded by Fukuzawa-sensei. New teachers were nurtured from within the student body. In other words, other than Fukuzawa-sensei himself, everyone was once upon a time Fukuzawa-sensei’s pupils. Furthermore, until the first year of the Meiji era, the school operated on a “half-teaching, half-learning” basis whereby senior students taught junior students, and juniors learned from their seniors; so those who were teachers were also students. In other words, the only true “sensei” at Keio was Fukuzawa-sensei.