My research has always been focussed on West and South Japan, and over the years this interest in the south as the route of exchange between Japan and the world is getting deeper.
A pilot study at the National Heritage Site in Kamuiyaki which marks the early stages of intensive exchange and trade in the seas between Japan, South China, and South East Asia, the Philipplines and Indonesia, was one step stone in generating my interest. First Christians, first fire weapons, first printing press, so much has come the southern route and is worth archaeological study. Not at least, the opening of Japan in the 19th century started from the south.
Archaeological evidence for contacts on the islands or covered on the sea ground, but historical records also give food for thought.