If your friend can't get his act together I really think you need to strike out alone. And unlike other posters, I don't think you should expend too much effort trying to motivate your buddy. Unless he has some special needs that you haven't mentioned, I think you should plan a full day of activities with an early start and if he's not ready to come along, don't worry yourself about it. (As Gen. Patton said: "Lead me, follow me, or get out of my way").

This is a reasonable list of cheap or free stuff to do in and around Tokyo. The other posters have mentioned some threads on Flyertalk with good ideas. I like the idea of getting into the country for the day, but YMMV:
http://tokyocheapo.com/living/101-fr...o-do-in-tokyo/

For lunch and dinner, try to find cheap and ramshackle "mom and pop" places. Sit at the counter. Carry a book or magazine to read if you like. If you're lucky you may find someone talks to you. If not, you can watch your meal being prepared and read a bit.

As for evening activities - It's tough when you don't know people, but there are some informal meetups that you can go to. Go with low expectations and have the courage to introduce yourself to strangers:
http://www.meetup.com/find/?categori...3&sort=default

With any luck, your buddy will realize that he's missing out and join you.