Daijoubu de gozaru. This unworthy one's wife died fifteen years ago, that she did. He has been wandering Japan for ten years since the revolution ended, protecting the happiness of those in front of him with an oath never to kill again, that he has. That is his answer, that it is... He is not "torturing" himself, that he is not. He regrets most of the decisions in his life, but he keeps on moving forward because to do anything else would cause Tomoe's death and the deaths of all those during the bakumatsu to be meaningless, that it would.

And... for the first time in all that while, this unworthy one has a "family" of his own, as patched together as it is de gozaru. He is... somewhat happy, that he is. They have given this unworthy one a reason to value his life again, that they have.

And Himura is this unworthy one's family name. You may call this unworthy one by either name, though traditionally we Japanese call others by their family name in order to be polite, and change to their given name as a relationship builds. What would you prefer this unworthy one to call you by de gozaru?