The Japanese language uses honorific suffixes for addressing people. Most of these suffixes are gender neutral, and are attached to the end of a person’s name, and can be applied to either the first or last name, if both are spoken at the same time, it is applied to the one said last.
Examples of these honorifics are:
“~ san （～さん）” is a title of respect added to a name. It can be used with both male and female names, and with either surnames or given names. It can also be attached to the name of occupations and titles.
Sama is a markedly more respectful version of san and can be used for any gender. It is used mainly to refer to people much higher in rank than oneself, toward one’s guests or customers (such as a sports venue announcer addressing members of the audience), and sometimes toward people one greatly admires.
“~ kun is used to address men who are younger or the same age as the speaker. A male might address female inferiors by “~ kun,” usually in schools or companies. It can be attached to both surnames and given names. It is less polite than “~ san.” It isn’t used between women or when addressing one’s superiors.
“~ chan （～ちゃん）” is often attached to children’s names when calling them by their given names. It can also be attached to kinship terms in a childish language.
Senpai is used to address or refer to one’s senior colleagues (lower rank black belts) in a school, dojo, or sports club. So at school, the students in higher grades than oneself are senpai. Teachers are not senpai. Neither are students of the same or lower grade: they are referred to as kōhai. In a business environment, colleagues with more experience are senpai, but one’s boss is not a senpai. In the same manner as English titles such as “doctor” or “professor”, senpai can be used by itself as well as with a name. A kōhai is a junior, the reverse of senpai, but it is not normally used as an honorific; kun is used for this function instead.
Sensei (literally meaning “former-born”) is used to refer to or address teachers, doctors, politicians, lawyers, and other authority figures. It is used to show respect to someone who has achieved a certain level of mastery in an art form or some other skill, and is also applied to novelists, poets, painters, and other artists. In Japanese martial arts, since typically refers to someone who is the head of a Dojo. As with senpai, sensei can be used not only as a suffix, but also as a stand-alone title. The term is not generally used when addressing a person with very high academic expertise; the one used instead is hakase (lit. “Doctor” but the actual meaning is closer to “professor”).