It was a few months ago, in mid-april but I was too lazy to sort out the 500+ pictures I took of the cherry trees. It's not Japan but I'm really happy that I got a chance to see the cherry blossoms at least once in my life! It's really impressive and beautiful, especially at night!
To get there, be prepared to fight a crowd and get down at National Assembly station line 9. I think the best time is to go on a late afternoon so that you can see the blossoms during day and at night.