Arnaud Mustier, 34, is a living symbol of success and excellence. Lawyer and hyperactive philosopher, he can be quite irritating sometimes. However, this apparent perfection is about to be shattered. A few pimples, odd behavior, and the diagnosis is made: Arnaud suffers from L.T.C.D., a rare pathology that makes male patients go through a late teen crisis. As he opens up to a whole new world of intense youth, he starts to seriously freak out the people around him - starting with his teenage brother.