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A gardener who was working in this park told me it was Sharinbai(sharin = wheel, bai = prum). I believed it. I told the womens who took walk for enjoying plants in the parks that was Sharinbai. But they asked me whether the fruit of sharinbai is black. They were right and I mistook the name of this fruit.
With the advice of Ya421 san, I can identify this fruit.
The name is tobera. The Japanese means "The tree of door."
(@けやきプール公園、阿佐谷北1丁目、Asgayakita, Suginami ward)