This would reflect my, up to now, only 'experience' of the sakura season.

Within Tokyo certainly, there'll be very little in the way of 'viewing'. You'll come across the odd rogue cherry tree in bloom, particularly in shady places. There are different varieties of blooms that flower so you should come across some fine examples of these from time to time - but for endless earthbound clouds of pink candyfloss - head North.

What you should be catching is Azalea season.
Tokyo becomes vibrant with pinks and reds. Seemingly every hedge in the city erupts into blistering colour.