What to expect with weather this week?

Hi everyone, sorry if this type of post isn't allowed. We are about to board out flight to Tokyo and can see that there will be rain this whole week. From there, will be doing hakone, Osaka, etc etc.

Has anyone seen the Japanese forecasts this week/ somewhat known what to expect?

Is this going to be must-staying inside rain, or grab an umbrella and get kinda wet rain?

Thank you 🙂