Responses
I think it has something to do with their role in the Maderury world. Like some sort of political burden or something. Like they have a lot of responsibilities like taking care of the mermaid, and who knows what else that hasn't been revealed. Thats why the kunimasa is pushing Norio away, now that he knows all this stuff he's gotta do for the rest of his life he doesn't want to drag Norio down into the thick of it.
So Shinobu and Kunimasa are bearing the burden of the Madarame family? Is the burden because Makio left her family? Or was it stuff before that?