luggage - to store or to ship?

I've read up on the options for what to do with luggages (lockers/takkyubin). My specific problem is that I'll be arriving in Osaka with a fairly large piece of luggage (a garment bag) that I will not need until I get to Tokyo two weeks later.

From what I understand, lockers can only be used for 3 days, and I'm not sure if there are luggage storage services at place other than airports? Or alternatively, I could ship my bag to Tokyo and have them store it for me? But would storing it for 2 wks be too much?

Thanks in advance for your advice.

If you stay at Keio Plaza or other middle to upper class hotel, they are likely to check your luggage until you arrive there.

You might want to contact your hotel.

The courier keeps delivery items up to 7 days.