Dont miss Takeshita Street despite the news reports overnight:
Takeshita is a short narrow street in Harajuku packed with shops selling subculture fashions. The street attracts mostly young shoppers and visitors to Tokyo. It has a loud and intense environment as shops on the street compete for shoppers.
The area has been associated with fashion subcultures since the 1970s. Most of the shops on the street are run by young business owners who are into such fashions. In recent years, the street is increasingly commercialized with chain shops popping up. https://www.japan-talk.com/jt/new/takeshita-street
Costs nothing to get in, & its not expensive to get out, be there !!
Mate, i am 40 and I've only been to NZ (3 times) and Bali for 4 days for by brother's wedding. I didn't mind it, but it really wasn't my sort of holiday. The trip to Japan is hopefully the beginning of more abroad international adventures for my family. Everything x 5 makes it expensive, we have decided to live in our small home and spend our money on travel and school fees (sob, sob, sob). No McMansion for me! ha
Use the train system it is quite simple once you get the hang of it and relatively inexpensive. They are an experience in themselves. Pay as you use & don't bother paying for long term tickets. The major train stations have shopping centres as part of them & food courts, etc.
Any idea of where are you staying in Tokyo?
I would recommend that you take the family to Disneyland & Disney Sea, if even only for a day at each. The kids will love it & I bet you will become a kid for a few days. (Yes I know you said inexpensive, but you have 12 months to put away $$). Disneyland is similar to Anaheim, Disney Sea is unique & like nothing I have seen in the past. You can get there by rail from Tokyo or stay close by at Tokyo Bay. There are some advantages of staying close by.
Mariocarts were fun & a different way to see Tokyo. Adults & licences only though. You can look them up via facebook & they are really helpful via messages.
Plenty of culture & shrines to see. Food is good, although one of mine struggled & unfortunately McDs & KFC were favoured by her.
Tokyo is massive & just wandering around is fun. Little trivial things can become an event. We needed to use a coin laundry in an inner suburb in Tokyo, & walking there, operating it & dealing with the locals was fun. There was a 7/11 next door so we sipped on a couple of drinks, while waiting.
The locals are great.
There is a Japan thread on BF, which is quite helpful.
Order a pocket wifi to pick-up on arrival at the airport and then google map your way around - maps incorporates public transport into your journey and tells you what line and platform to be on, which is super helpful. Trains are relatively easy to navigate once you get the hang of it though.
Would recommend staying in Shibuya or Shinjuku areas if possible - central but will be pricey with a family.
Drink cans of alcohol from vending machines It’s cheap and you’ll have fun. Maybe even hire a schoolgirl if you have a teenage son that’s his holiday sorted. Otherwise cans of alcohol from the vending machine is all you need