Hi Simace,
Living in Leicester we are a bit short of Japanese produce, but I buy online from these people, always a prompt service and a good range of stuff.
https://www.japancentre.com/en
I know they have what sometimes looks like a bewildering range of similar products, so I just plump for the one with the best rating and so far it has worked.
Edit: sorry for the slow reply, new year and all that.