Hey I just got back from my first trip to Japan! Awesome experience. Similar to you it was my first time out of the US, don't know Japanese and was just excited for some traveling. I didn't go as far North to Ebisu but did visit all around Tokyo and actually rented an R34 GTR while I was there to drive to Fuji on some nice roads.
Honestly just Youtube a lot before you go, some pointers:
- Read up on cultural norms so you aren't a sucky American tourist
- Learn how to use the public transportation. Since I for the most part stayed in Tokyo area I just got a PASMO (look it up). Otherwise if you plan on checking out Kyoto and Osaka look into JR pass. Google Maps is extremely helpful with picking the right lines to take!
- Look into a wifi box rental. I chose this path over a pre-paid phone or SIM card. Super easy and relatively cheap (I paid the $30USD for a week of service) and you use your own phone.
- If you do rent a car, realize that most roads are piss slow (80kmh speed limits) and tolls are extremely expensive and can be confusing.
- Exchange rate can vary so I would wait until your over there to pull out yen, 7/11s are the best over there.
GTR I rented:
Good luck dude! I had a blast and would love to travel outside Tokyo more next time I go (hopefully soon). I have heard good things about Powervehicles as well but I don't have any personal experience with them or driving on tracks over there.