Thanks for reply.
But I think it's not obvious that "plotHighlightEffect" affect after mouse pointer escaped legend area.
Also, without alpha option at "plotHighlightEffect", alpha property of data is gone.
Alpha property at data is it's own property of data that should be shown properly and "plotHighlightEffect" is a option just for easier use.
So, there is no way to keep alpha when using "plotHighlightEffect"?