Are ther luggage lockers at Harumi Wharf?
As far as I searched, Wharf doesn't have coin lockers. However, the shopping mall near the wharf has Coin Locker.
I'm not sure what do you want to store but seems they don't have the big one, the only locker for handbags.
You can check the mall and coin locker here.
In "Available services" section, you can check the info about the locker.