Hi, I am trying to look at fares for a one way booking from ICN to Tokyo (or elsewhere in Japan)

When I look at the Japanes site I can only look at destinations starting in Japan, similarily with the UK site only from the UK, when I look at the Korean site, there is only a function to check the itinerary, is there a way to look at fares and book online this flight?

many thanks

sorry, should clarify that I live in the UK