Most of them are second- or third-generation immigrants and they come from the same outlying areas of Frankfurt that were at the centre of the major anti-terrorism operation on Wednesday. Not far away stands the prison where Obino and the Italian production company TFilm have managed to film for the first time ever, after convincing the German authorities of the validity of the project.
The documentary is titled 'Bare-Handed - A mani nude' and is the object of a crowdfunding campaign that has just been launched. Filming is underway, but already the trailer and the first video clips speak volumes about the rehabilitation programme devised by stage director Arne Dechow and Martin Meyer Husamuddin, a German Muslim convert who has become the prison imam.
Mustafa's confession is significant. "Here in Germany you cannot pray in peace, you are discriminated against. I have encountered many recruiters: they say it's great down there, that you can live according to Islamic principles. That you can fight for Islam, but if you don't want to you can just live there," he says.
"ISIS? I don't know exactly," he continues. "On the one hand they look like terrorists, on the other people who want to live out their Islamic faith in peace. And so I find myself in this dilemma, I can't tell Good from Bad."
Obino says this testimony shows how ISIS represents "an opportunity for social elevation, a sort of cultural identity.
Other young people told us: 'If we go to Algeria we don't feel Algerian, here in Germany we are not German'. And so for them the Caliphate becomes 'home', a place where they can be themselves over and above jihad".
The 'work in progress' also highlights the anger felt by some of the prison inmates such as Aidin, an adolescent of Tukish origin who was picked on at school as 'the Muslim boy' despite not being a follower of Islam. "Far from the institutions in Brussels a director and an imam are trying to create a new, inclusive rather than marginalising European culture," Obino concludes.
Luciana Borsatti, ANSA
Luciana Borsatti, ANSA