Darvond: So, who flunked their Japanese Honorifics lesson? Chan is just a suffix added on to a name, akin to tan, san, sama, domo, and so on.
RWarehall: So you don't see the natural connection some might make to 4chan? And I see you think you are quite the expert on Jaoanese honorifics huh?
From the "chan" entry of wikipedia: "Chan" is only used between people who have known each other for a long time or who are of the same gender. Otherwise, using this for someone, especially adults, only known for a short period of time, can be seen as offensive.
To you, it might be "just a suffix" but words in a given culture tend to have specific meanings and usages. Which was my point. Picking the wrong suffix at the wrong time, can be offensive.
I really, really think it's time we point to 松本人志さん (Hitoshi Matsumoto), who referred to himself as 松ちゃん (mac-chan) in his show 放送室 at the beginning of many episodes, which you can hear clips from on youtube. It's not unusual for these suffices to have extended uses for specific implications: for someone willing to look silly but also appear very close to his audience, it's something a male may intentionally try to get others to call him. "-chan" is basically "-y" in english. Kitten, to be all cutesy, becomes "kitty." Cathrine becomes "cathy." "Shane" becomes "shaney" or "shaney-poo," "John" to "Johnny" etc. Women tend to be more accepting of it for that reason. Vs the "male equivalent" of "kun" which can be written "君" which also doubles over for "kimi" which is a sort of polite second person pronoun (which is still avoided like the plague). So if "neko" means "cat," then "nekochan" means "kitty." The nice thing about this, and why weeaboos stick to it, is because there are weeaboos who don't get it, but even the ones who are in the know, understand that for someone with a name that already ends with "y" (like someone who was named "kathy" instead of "cathrine"), it usually doesn't work ("kathy-ey"?), but chan always does ("cathy-chan").
Also, ちゃん is can also be written "tyan" since it falls on the "t" row, which is where the "chan"/"tan" confusion comes from: it's tan vs tyan, in pure phonetics, since they make the "ch sound" differently.