As of now, there's no definite news indicating that Lena Dunham is writing a romance novel. She has been involved in various other creative works, like her previous works in television and film, but no signs point to a romance novel in the works. Maybe in the future she might explore this genre, but for now, it seems not to be the case.
The real story of 'Green Street Hooligans' is quite complex. It delves into the world of organized football hooliganism. These groups are not just about random acts of violence. They have a sense of loyalty to their own 'firm' and a deep - seated hatred for rival ones. There are often territorial disputes and a desire for dominance within the football - hooligan subculture. The movie tried to capture this reality, showing how young people can get drawn into this dangerous and often criminal world. It also shows how difficult it can be to break away from such groups once you're involved, as there are strong social bonds within these hooligan firms.
Well, without having read the 'Green Dolphin Street Novel', it's hard to say precisely. However, it might center around a particular mystery or drama that unfolds on Green Dolphin Street. Maybe there are love stories, family feuds, or secrets that the characters are trying to hide or uncover within the context of that street.