You know, you will enjoy your trip more if you do at least some of this research yourself.

The tram I mentioned is the ropeway to the top of Mt. Moiwa. The botanical garden is owned by Hokkaido University and is right next door. Most fish oriented markets in Japan are really only open in the mornings. They are there to sell the day's catch to locals. You might find some of the stores open in the afternoon but most of the crab, fish and such will be gone. Those little, local markets are always called "morning market." They aren't like Fisherman's Wharf in SF, that is an all day tourist trap.

Here is a pretty good guide to Sapporo that will help you with the above and a lot more:

http://www.japan-guide.com/e/e2163.html

And one to Hakodate:

http://www.japan-guide.com/e/e5350.html

The Museum of Northern Peoples is just off the main streetcar line in Hakodate, near the Suehirocho stop:

http://www.hakodate.travel/en/things...thern-peoples/

As for sakura in Tokyo, if they are in bloom, you should find plenty in and around Asakusa. Senso-ji temple has some as does the riverside park. Ueno is only 2 stops away on the subway and Ueno Park is quite near the station. Aside from cherry trees, Ueno Park has the National Museum, which is worth a visit.

Another, interesting way to see the sakura from Asakusa is to take the water taxi down to Hama Rikyu Imperial Garden. This is my favorite viewing place. The last time I visited during sakura season, the place was awash in pink and very beautiful. From Hama Rikyu, you can walk to Tsukiji Market or Ginza - or just buy the round-trip ticket and return to Asakusa when you are finished. I don't know your mom but can almost guarantee she would love it.

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