Now that I think about it. How did Kuru win over his mom? I remember one of the earlier ones Kuru mentioning something about getting his mom’s permission to live together when they were in college.
And so, the inter-families approvals begins, starting with Mayu (or basically between the younger sisters first)
and then probably the mother(s) (like how Sakuragi-mama, who approved of Kuru moving in with Sakuragi-kun later on after they graduate from high school)