Confused trip

Hi,
We'are family of four, visiting Japan from 21st to 28th. We plan to be in the center of Tokyo from 23rd to 27th of March. We are planning to use the day we arrive 21st and 22nd to visit else where from Narita. Can you please kindly plan a trip for us for the 7 nights bearing in mind that we have 2 kids. Particulary we want to visit Mount Fiji as well.

Suggested itineraries:

http://www.japan-guide.com/e/e3051.html

You can also view details of individual attractions here:

http://www.japan-guide.com/e/e2164.html

My first question would be:

How old are the kids?

This matters because if I was wanting to go to a theme park, I would take a younger child to Disneyland, but an older child to Fuji-Q.

http://www.japan-guide.com/e/e3016_land.html
http://www.japan-guide.com/e/e6918.html

I would consider going to Nikko and Hakone. While near Nikko, I would think about going to Edo Wonderland. At Hakone, I would do the round course.

http://www.japan-guide.com/e/e3879.html
http://www.japan-guide.com/e/e5210.html

There is a small zoo in Ueno Park, and Enoshima Island near Kamakura might also work for you.

http://www.japan-guide.com/e/e3019.html
http://www.japan-guide.com/e/e3117.html

I mentioned Ueno Park and Kamakura, because these are very good cherry blossom locations.