Kinda interesting that the Nagasaki monument is a poem about another guy who got exiled at about the same time as our boy from the last chapter, Tametomo. Anyway, the stone in the video is the stone in question. I think I went wrong by assuming that it was a memorial to the man as opposed to, you know, a poem.
Unfortunately understanding century old poems, let alone translating them, is beyond my ability. It has something to do with squeezing oil out of camellia flowers to wash your hair, though.