I don't know any Japanese either but I clicked the big orange button that looks like a sort of shopping ... wheel barrow... maybe.. and got a similar sort of Shopping Basket looking page... looks like you have to register/make an account to order, though because there's two boxes below that and one says ID at the end and I assume the other is for password? The button above the double boxes is probably the "create new account" button.
Thank goodness ordering pages are similar everywhere...