Hello, I live in Tokyo 👋
It's actually cheaper to travel to Japan now because yen is low compared to usd. I think that's also the reason why there are a lot of tourists in the country nowadays.
Eating out can be one of the reasons why you spend a lot during traveling. Luckily there are affordable options in Japan and even in Tokyo. Try to visit local shops rather than expensive or famous restaurants esp those serving wagyu or luxury sushi, and you'll be fine. Don't spend too much on convenience store stuff and you'll also be fine.
Accommodation? I'm not sure if coachsurfing is still a thing but way back then it was. I was even a host back then. But if not anymore, maybe hostels or backpackers inn are your cheaper alternatives.
If you want to go out of Tokyo, try to avoid the bullet train if you want to save money. There are cheaper commutes like taking the bus (day bus or overnight bus) or train passes. For train passes, it's expensive to buy the JR pass - there are more passes other than this that can make you save money.
Thank you so much, this is all very helpful information and I am putting it in my log right now. This is the sort of insider information that I really like to see.
I remember couchsurfing. I was a host for a while as well and it was fine until one day a couple stayed with me and stole from me. That was the last time I did that but it was a nice concept for a while there.