"He remembered how repulsed he had been that these foreigners could kill so cruelly and his fear that they might kill him..." This memory is important because it shows how scared and nervous Manjiro was on his first whale boat. Now Manjiro is holding a lance himself.
Words of The wiser
"Years ago, he and his friends found a school of Mackerel before the storm..." This memory is important because it reminds us of how Manjiro Ended up on this ship.
Words of the Wiser
"Manjiro remembered the first time he had been in a whale boat and had turned to see Jolly Standing where he stood now." This memory is important because it gives us a comparison of the 2 moments.
Words of the wiser
"America is working to develop its own country. It has no time attack other countries." This message is important because it tells the lord of Japan that America doesn't want war. This might fix the relationship between America and Japan.
A truly strong hero does not resort to violence unless it absolutely cannot be avoided." This message is important because it will prevent Manjiro from getting into a fight. This teaches Manjiro that fighting is never needed.
Be careful of what you say, its not like America. This message is important because it warns Manjiro of what will happen if he says something he shouldn't, especially because his life depends on it.