I Go to Koubun-kan Museum in Ibaraki Prefecture

I went to Koubun-kan museum with my wife on a warm sunny day a couple weeks ago.
Plum trees were in full bloom.
I don't know the name of it but the bird were busily sucking nectar from a branch to a branch, from a flower to a flower.

FYI: After posting this article, I was informed that the name of the bird was bulbul.