Japanese. Honorific suffix used for people with whom the speaker is familiar. See discussion of honorifics below.
Honorific. Used in the modern day for male students, or those who grew up together, but another usage -- the one you're more likel to find in Rurouni Kenshin -- is the "superior-to-inferior" form, intended as a way to emphasize a difference in status or rank, as well as to indicate familiarity or affection
suffix; usually attached at the end of a boy's name to express affection
honorific used when addressing males from high-school through college age
a diminutive honorific suffix, usually used when addressing young men or boys
suffix usually added to a boy's name, used by friends or someone older than the boy. Kind of like adding a "y" to English names, such as making Bob into Bobby. See also -chan and -san Li - the notation this website uses to denote the character in CC - the loud, wise-cracking little beast that bears no resemblance to Li-kun of CCS.
appended to a boy's name; politely familiar term. When the girls thought that Seiya was a boy, they called her Seiya-kun; Luna refers to Mamoru as Mamoru-kun. High-school boys are often referred to with -kun. Also used by a socially superior male when talking to a socially inferior male.
An honorific used either to address a male well known to you or to address a junior colleague of either sex
School creed. Also, bo or staff.