On the topic of gaijin, I suppose I could enlighten back when I went to Tokyo and Kyoto a couple years back.<br/><br/>Me and my SO heard it a lot when we were walking through the streets etcetera. There were a few cases where we were made aware that gains were not allowed, one of which being a mixed bath at a hot spring inn. Likely due to ill experiences with foreigners showing poor manners in shared baths in the past.<br/><br/>The word isn't meant to hold ill intent, it's more so an awareness alert that gets thrown around far too much. It's more of a "That is a foreigner, so don't expect him/her to necessarily follow our culture properly". The stigma with it rests with how alienating it is. As tourists, we weren't very bothered by it, but for someone staying in Japan for a prolonged period of time, I can see how it could be bothering, considering it's a stamp given purely by your looks. You can have perfect Japanese and follow all cultural norms and you'll still be considered a gaijin by people who don't know you.<br/><br/>For honorifics:<br/><br/>-San: Basically anyone you're not on first name basis, who has an equal standing with you.<br/><br/>-Kun: Most frequently used for boys. Not very different from san, but gives it a slightly higher regard. Used between friends or lovers not on first name basis most frequently.<br/><br/>-chan: Affectionate honorific, means "friend" in broad terms. Not that frequently used as you grow older in other than joking natures, since other honorifics or first names usually suit situations better.<br/><br/>-Senpai: Someone over you, albeit not by a landslide. For a school setting, it's an upperclassman (Equivalent for underclassmen is "kohai", but is rarely used, san/kun are more common), in an office setting, it's someone who you consider over you, but it's not your boss. It can simply be someone working with the same thing you have, but that have done it for a longer time, though this is less frequent.<br/><br/>-Sensei: A teacher of sorts. Can be a normal school teacher, or someone who has mastered a craft and is teaching it on. Typically, traditional swordsmiths that are teaching new generations how to smith would be considered sensei, the equivalent for tea ceremonies etcetera.<br/><br/>-Sama: Someone you consider in very high regard, to the degree of royalty. Not very frequently used though.