Sensei

Sensei is 先生, born earlier. It addresses teachers, but also doctors, lawyers, politicians and manga artists, and it works as a title on its own without a name attached. That range is why the English subtitle track keeps switching translations. The same word coming out of the same mouth can mean sir, doc, teacher, or a level of respect that English has no single word for.

It also does sarcasm. Said flat, with the wrong stress or to someone who has not earned it, sensei needles. Anime uses that constantly: a student calls a teacher sensei while doing exactly what the teacher forbade, and the honorific becomes the joke. Kakashi in Naruto and Gojo in Jujutsu Kaisen both get addressed that way by pupils who plainly consider themselves the adult in the room.

The mentor built on the word is a fixed piece of the medium's furniture. He or she is powerful, evasive about it, teaches through a method that looks like nonsense, and is often absent when it matters. Jiraiya, Master Roshi, Kamina and half the sports coaches in the canon run the same job description with different hair.