I got all of this until you added "emo" in there. How can you be cheerful and emo at the same time. Maybe if emo actually meant "emotional" but from what I see, emo people seem to lack emotion entirely. The don't care about feelings. Whether it's with themselves or other people.
Well...nothing definitive. Though I believe the actual unsullied definition of "emo" is one who is connected with their emotions, the majority of those described as such are black-garbed teenagers who enjoy being depressed for no good reason and taking selfies.