You may, even now, be too late in arranging an internship. You DO realize that everyone in Japan wants a media internship too? It's pretty competitive even before the gaijin apply. I'd suggest you contact the Nambu Foundation, they have an internship program with a stipend but it won't cover everything. You could also contact JETRO to see about internships. I'm pretty sure you can contact both Nambu and JETRO through your nearest Japanese Embassy or Consulate.