Do it! It's a wonderful experience, especially if you have roots there.
For anyone who's interested (especially those in the US), the dollar is strong right now so you'll get an excellent exchange rate.
Japan makes it very easy for people to travel and are generally welcoming towards tourists. Here are some simple tips to travel in Japan on the cheap:
For flights, check for off-peak rates, usually in the summer and winter. I don't recommend traveling in July as it's the rainy season and humid as hell. I've traveled to Japan in the dead of winter on purpose and it was lovely, with the snow in the mountains and all that. If you don't mind the cold, go in early winter. And besides, most places in Japan aren't that cold in winter. In general, think US mid-Atlantic (like DC, MD, VA) in terms of average temps. Avoid early May as it's Golden Week and will be an intense amount of travel done by locals.
Very, very important: JAPAN RAIL PASS. The best travel bargain you can hope for, allows you unlimited rides on any JR train, bus or ferry, and this includes the bullet train (shinkansen) as long as you take the unreserved seats. Doesn't work on private rail lines of course, but you can literally travel the entire country on this pass.
Stay in hostels. If you don't mind bunking with strangers, especially, but if you're traveling with a friend (same gender) you can pay a little more for a private room. Some recommendations:
-Yoyogi Youth Hostel if you're staying in Tokyo. The only drawback is you have to ride the private subway to get there unless you want to take a loooooong walk from Yoyogi Park. (I don't recommend that when you're checking in. Just pay to ride the subway.) All private rooms, with shared toilets and communal baths. No curfew! Plenty of restaurants, convenience stores, even a grocery store nearby for cheap food.
-Any K's House. I think all of them come equipped with a full kitchen so you can cook meals. Shower stalls, too.
-If you want to stay a full month in Tokyo, look into booking a room or bed in a Sakura House.
Food...well, this really depends on how frugal you want to be, honestly. My friends and I got through with 100 yen bread or onigiri and cheap tea for breakfast, a 1000 yen or less special at whatever restaurant we felt like for lunch, and bento, instant ramen, or a combination of both for dinner. We went to "nice" restaurants a few times, as well.
If anyone has any questions, feel free to PM me!
Source: lived in Japan as a student, traveled there five different times.