It was great experiencing hanami in Japan even at least once in your lifetime and one of the popular and best place to go is Shinjuku Gyoen in Tokyo.
Shinjuku Gyoen is home to a huge number of cherry trees of different varieties and has extended viewing season from mid March to late April. So other parks might not be in cherry blossom season anymore but Shinjuku Gyoen still is.
It is a 15-20 minute walk about 700m from JR Shinjuku station New South exit or 5-10 minute walk from Shinjukugyoenmae station on the Marunouchi Subway line. We took the JR Shinjuku station route when we went there and took the Shinjukugyoenmae station afterwards. The best tip I can give when in doubt, use Google maps. 🙂
Operating hours from 9 AM to 4:30 PM with last entry at 4 PM. Entrance fee is 400 YEN for adults and 50 YEN for children.
I hope to go back someday!