There is SAKURA at every city in Japan. Cherry blossoms will open from tropical area in late March and early April. If you come to Japan in late April, it is better to go to TOHOKU district, north Japan.
Please check nice photo in my blog as follows. You can see SAKURA. There are the pale pink flower and dark pink one. 
東京・新宿御苑

https://ameblo.jp/cx0293/entry-12451854359.html

More information.
In the middle of April; I can recommend Yamanashi-Ken, because of nice contrast pink with yellow. Pink peach blossoms match to yellow rape blossoms very well below.
山梨県・笛吹市春日居町

https://ameblo.jp/cx0293/entry-12452483471.html

In June; I can recommend Kyusyu. Kyusyu is very far from Tokyo.
九州・大分県・くじゅう連山

https://ameblo.jp/cx0293/entry-12436639897.html

Caution: Some flower season is very short, and it is variable every year. Then please check it before you go to these spots. t