What are the prefixs in Japanese?

Answer 1

If you are meaning Mr./Ms./Mrs. etc, then they are actually suffixes said at the END of a person's family name, or first name. Example is Hayozaki-san = Mr. Hayozaki.

For first names, in Japan it is considered impolite to refer to someone by their first name unless you know them personally. But it such a case, you would say Sakura-san, meaning Miss Sakura.