About an hour by express train from Tokyo (Kinshicho), Satte is on the way to Nikko in Tochigi Prefecture. Satte is famous for these cherry blossoms (sakura) and rapeseed flowers (nanohana) blooming together in a long, riverside park called Gogendo Park. A splendid “collaboration” of pink and yellow (and green) in early April. Very impressive on sunny days with the bold blue sky, dainty pinks, and radiant yellows. Well worth the trip from Tokyo. I also like the meaning of “Satte” (幸手) which means “happy hand.”
Gogendo Park is a large park along an embankment lined with three rows of cherry blossoms. Both sides of the embankment have one row of cherry trees, and the top of the embankment has another row of trees along the pleasant pedestrian walkway (cherry blossom tunnel).
The cherry blossoms go along the embankment for 1 km. That’s quite long, but it was originally a whopping 6 km long. Many of the trees were cut down during World War II for firewood. The ones we see today were planted in 1949. The rapeseed blossoms were planted much later in 1988 where there used to be rice paddies. In the upper photo, the rapeseed blossoms are only 80% bloom. Such a picturesque place for wedding photos, portraits, etc. 
More photos: https://photoguide.jp/pix/thumbnails.php?album=1120
From Tokyo, get on the Hanzomon Line or go to Oshiage Station (Skytree) and ride the express train (Kyuko) bound for Minami-Kurihashi or beyond. Get off at Satte Station on the Tobu Nikko Line (東武日光線幸手駅). Takes about an hour from Kinshicho or Oshiage Station. From Satte Station, there are infrequent buses to Gogendo Park. If you can’t wait for the next bus, walking will take 30 min.