I think it might go towards Japan - but you should be right by the 9th. Would have to do a major stall to drag out that long. Also the waters up north might be too cold to sustain it, being so early in the season.

More of a concern is will Guam still exist by then?

Interestingly, CWB's week-from-today map shows a steering-ridge high building quickly into the north, which brings northern Taiwan back into play. It's whether it follows that cold-front up before the high builds in or not.

Guam satellite link - it's all happening there as we type: https://www.goes.noaa.gov/guam/guamloops/guamircolor.html