We got IC cards (ICOCA) in Osaka for 500 Yen each, and used them for 2 weeks travelling across Japan this March. Worked like a charm, only thing that's annoying for us tourists is how it is a stored value card and needs to be topped up. I think we still had like 500 Yen on our cards when we departed, even though we bought a lot of stuff with it on the last few days.

While we got ours at the Osaka airport (KIX), I am sure I saw the "purchase a new SUICA/ICOCA" options at a few terminals while topping up. I suppose you mixed up the "Welcome to SUICA" tourist card (available at fewer locations) with the normal one? I was under the impression there was a lot of confusing information floating around online.

But I agree, public transport in London is - as a tourist - more straight forward. Just a matter of spotting the terminals at some stations IIRC. OTOH in Japan we found no station with an elevator smelling like someone used a hippie bus as an emergency toilet ;-)