I'm at the part when they're home after finishing the battle with the bantou.
As from that, Sado & Inoue hasn't appeared that much in the series.
Are they going to appear more, further on? 🙂

You're talking about the anime? Well the Bantou Arc was filler so it's not really going to follow the story also I haven't watched that part in a very long time, can't remember.