San, sometimes pronounced han in Kansai dialect, is the most common honorific and is a title of respect similar to the English words “Mr.”, “Miss”, “Mrs.”, or “Ms.” However, in addition to being used with people’s names, it is also employed in a variety of other ways.
Chan is a diminutive suffix; it expresses that the speaker finds a person endearing. Thus, using chan with a superior’s name would be condescending and rude. In general, chan is used for babies, young children, and teenage girls. It may also be used towards cute animals, lovers, close friends, or any youthful woman.