 Léon, a humble civil servant, has the unusual ability to walk through walls, however thick they are. One day, he falls madly in love with a charming hotel thief by the name of Suzan. In order to impress her he poses as Garou-Garou, a dangerous gangster. Mistaken for him, he is arrested and sent to jail but he, of course, leaves his cell(and comes back to it) just as he likes, infuriating the prison warden. But, despite this wonderful gift, he remains shy in the presence of Suzan...