Going to Japan! Looking for advice (travel, culture, reccomended places to visit, etc.)

So, like the title says, I'm going to Japan. I'm leaving around mid-march and staying until the end of July! (So a very long visit!) First, I am spending a week or two in Tokyo, visiting my boyfriend's brother and his wife. Then my boyfriend and I go up to Akita, to attend Akita International University for a semester abroad. :) I'm really excited! I was wondering if the Justbento community who has traveled to Japan has any tips, suggests, or advice for me? I'm interesting in ways to save money, fun things to do, little unknown cultural info to look out for, etc. Although I'd like to point out that I am relatively familiar with Japanese culture and I do speak a considerable amount of the language. However, I'd really appreciate anything you have to say! Thanks :)