Size 29 (EU 44.5) socks in physical stores in Japan?

Hello!
I'm traveling to Japan tomorrow and at first I thought I'd buy all the socks I need at Uniqlo, but now I'm getting mixed information that larger size (27-29) socks are online order only while also getting some information that larger Uniqlo stores such as the one in Shinjuku and Ginza have the size in stock.

Which case is correct?

If they don't have my size in stock is it possible to enter a store and order them there?

Thanks!