Closest train station is Hinata-Wada Station. To get to Hinata-Wada, you have to change trains at Ome Station on the JR Chuo Line. 日向和田駅
Sadly, spring 2014 was the last time we could see these trees. The plum trees were infected by the plum pox virus and the city cut down all the trees in 2014 to wipe it out. These photos were taken in 2006 when the plums were still fully glorious. Good news is that they have been replanting since 2016.