Looking, in some ways, like a viking ship, the draincover for Imabari on the northern tip of Ehime in Shikoku depicts some ships belonging to the Murakami Suigun, sometimes described as a "navy", but more often described as pirates who operated in the Inland Sea between Shikoku and Honshu. On the island of Oshima just off the coasst of Imabari and now a part of Imabari City is a big museum devoted to the Murakami Suigun.
On Innoshima, another island in the Inland Sea, now a part of Onomichi City, Hiroshima, is the Murakami Suigun Castle, a base for the "pirates". The ships have quite a different style.
The town of Miyakubo on Oshima has a depiction of one of the pirates on its draincover. Just like everybody in Japan and Japanese history he is happy and cute. No robbery, murder, pillage or rape for these pirates.