Generally speaking, the cherry blossom season in Japan is between the end-March and the mid-April but it depends on regions and especially species of cherry trees.
I went to see early cherry blossoms in the area of Kanto region famous for that. After walking on a small beach and tasting yummy local food (local raw fish), I started enjoying marvelous cherry blossoms with sunny weather…really nice walking ! There also facilities for the hot spring geyser, the foot bath and hot spring bath (hot spring bath isn’t free though.
(by Super Yossy)