Ditto!

Because you don't have a whole heck of a lot of time, you might consider a guide for your first day in Tokyo. We used Backstreet Guides (a tip from another traveler here) and had a lovely very young woman that I think your teens would relate to. She kind of greased our entry into Japan by teaching us how to use the public transport. Plus, we saw SO MUCH on that one day because she knew where to go and how, and without her we would have wasted quite a bit of time trying to figure out the logistics I'm sure. I have traveled a lot with my kids, and I find that sometimes kids are in a much better mood when somebody besides mom and dad are in charge. Especially the first day when you want to go-go and they'd like to sleep. Eliminates the eye-rolling for sure. Our young guide was very into Japanese pop culture and we loved her tales about that. Backstreet books up during the cherry blossom time, which you're close to, so if you're interested in that, book as soon as you can.

If you want to use a guide, you might consider taking advantage of a local “goodwill guide” – The Japanese National Tourism Organization coordinates free volunteer guides who are knowledgeable and happy to guide you in return for practicing their English – which can be excellent!
www.jnto.go.jp/eng/arrange/trav…
You pay any entrance fees and his/her meal if your time with the guide includes one; do not tip them (or anyone else in Japan)!