Studying in Japan with medications

I've been interested in studying in Japan for quite some time now, but I have a handful of medications I need that I can definitely not go without. I'm first and foremost worried about my ADD/ADHD medication Focalin. From what I've read I can only bring 2.16g (about a 3 month supply) with me. Obviously if I'm studying for any period of time that wont be enough, unless I leave and come back every 3 months. I also would need to see a doctor every 3 months or so to check my thyroid levels as well.
I've heard about getting a "Yakkan Shoumei" for my medicine but It's difficult to find good information on it. Any information or input is very appreciated, thanks.

The Yakkan Shounmei is a permit to bring medication above the quantity normally allowed. You need to obtain it from the Japanese authorities before departure.