An entire subculture of people (usually angsty teens) with a fake personality. The concept of Emo is actually a vicious cycle that never ends, to the utter failing of humanity, and it goes something like this:

1. Girls say they like "sensitive guys" (lie)
2. Guy finds out, so he listens to faggy emo music and dresses like a dork so chicks will see that he is sensitive and not afraid to express himself (lie). He dyes his hair black, wraps himself in a stupid looking scarf, develops an eating disorder, and rants about how "nobody understands".
3. Now an emo guy, he meets Emo chick and they start dating, talking about how their well-off suburban lifestyles are terrible and depressing (lie)
4. Emo guy is just too much of a wussy. His male sexual organ is too small, he's too depressed to bathe, and has more mood swings than emo chick, and he doesn't even have a menstrual cycle. Emo chick dumps him, saying "It's not you, it's me." (lie) as she drives off with Wayne, the school jock and captain of the football team.
5. Emo guy goes home and cries, proceeds to write a weak song and strum a single string on his acoustic guitar. Another emo chick sees how he is so in touch with his feelings, and the cycle continues.

This is the sad truth of the emo lifestyle/music, and now that I look at how pathetic it really is, maybe the emos DO have something to cry about!