In manga, shoujo is one of the sub-genres and is perhaps the most popular one of all of manga.
It's thought of generally as girls manga as opposed to shounen which is boys action. However, there's a lot of boys who really like shoujo because it features intense characters. Teenagers going through angst, and they're troubled with relationships, and they may have adventures. And so it's very compelling for everybody.
The thing that people like about it, and you will probably recognize if you don't know already, is they have giant glistening eyes that are so attractive. And the small noses and mouths and features. The faces are subtle, large, so they are young looking. Their bodies are generally simplified so it's not too tough to draw. I'd say that this is sort of like between easy and medium as far as drawing it.
Now, there're very popular characters that you'll know that come from the shoujo genre. There's Cat Girls, there's School Girls which is just really popular. There's Magical Girls and there are also the boyfriends of the School Girls.
And there are two styles of boyfriends. One is the kind of loyal, heroic, young 14 year old who never gets the girl. And then there's the kind of older, teen idol guy, good looking, mature, and he always gets the girl but doesn't really care about her.
So here is a School Girl type that is a shoujo style. She's kind of young and perky, that's kind of looking cute. And here is the bishoujo type which is actually also a shoujo type genre. And he's the kind of good looking guy who is unattainable by the girls.
So as you can tell by my just describing the characters, there's a lot in there. And all of a sudden stories come together.
So that's the shoujo genre. Give it a try, you might like it. It's perhaps the most popular style of all of manga.