That old guy must be the protagonist of the other game, Muneyoshi.
Also I think there's a slip in the dialogue. Like, I don't know what the original text is, but "Edo residence of Mito domain" sounds awkward. It is a reference to how in the Edo shogunate period domain lords of a certain status are required to have a residence in the Edo capital for official business (江戸藩邸 Edo hantei). It feels like it would have been better written as "The Edo residence of Mito domain's
lord" or "the Edo residence
for Mito Domain".
Also
of course there's going to be some random thuggery going on. If we're having a "Mito domain lord" we have to play "
Mito-Koumon" LMAO. Our fake Ye Olde Japan setting is never complete without a Mito Koumon parody.