Notes taken while watching the episode:
The three siblings aren’t actually related at all (kinda like Momoka, Tabuki, and Yuri).
Shouma found Himari (Not Kanba as we anticipated since the beginning of the series)
Kanba is Masako’s brother
What I’m speculating:
The dad is also Masako’s dad.
Nothing else really. Its hard to speculate on an anime that’s very unpredictable.
The thing that I guess I liked the most in this episode, is the cute relationship of Shouma and Himari. Though I kinda lol’d how they’re speaking of such difficult terms when they’re fucking kids.