Japanese question

So I started Fruits Basket (just a few pages in, but it's definitely promising). I know people have explained this to me before, but I'm already getting lost with all the forms of address in Japanese. My understanding is that -san denotes respect and -chan denotes affection (and I realize I'm probably missing all sorts of nuances there), but what does -kun mean? Are there others I need to remember?

P/N drabble for 30_fantasies

Title: By His Side
Fandom: FFX-2
Rating: PG-13
Pairings: Nooj/Paine
Spoilers: Minor, for backstory.
Notes: This fic was written while I was playing with making a P/N soundtrack and with the idea of writing a song for each story. I quickly concluded that most of these wouldn't make a full story, but I did get this drabble for my 30_fantasies claim out of it. Posted for the theme Death; inspired by "By My Side" from the musical Godspell (the original stage version, not the movie). I may still post the FST and related scribblings eventually, depending on how it comes together.

It was a journey he had intended to take alone...