The only thing that bothers me is how Ushi behaved with Sono (the prostitute.) It's like he either forgave her or forgot about what she did. Why did Imuta go to his village? He knew where it was from before getting info from Sono and wanted revenge. But why did he kill Ushi's sister and his mom? Because Sono told him, Ushi had told her his sister looked just like her... so she is part of the reason why his sister died.
I guess you could say, "Well, maybe he thinks Imuta came to his village and force the villagers to spit out who Ushi's family was," which actually makes more sense, if you didn't know Sono told those things to Imute... but it still pisses me off. I guess that if Ushi knew Imuta was asking about them in several brothels, he would probably piece out the pieces, but he doesn't know. He only knows Imuta liked banging Sono and the Satsuma found out the brothel they always went to...