I don't know if this is what you guys mean, but I'll try to explain the relation of the Gong siblings. Gong Zishang, Gong Shangjue, Gong Ziyu, and Gong Yuanzhi are like cousins to each other, they all have different moms and dads. They are family from different lineages, think of it as like their grandparents are cousins. That's why they're still calling each other as brother or sister. Gong Zishang and Gong Ziyu are so close since they were children, while Gong Shangjue took Gong Yuanzhi and acknowledged him as his brother since his family and Yuanzhi's parents died.
*Each lineage has a different role and responsibility in Gong family.
The mother and her 5 daughters and an adopted daughter are all the female leads.
the FL is all the sisters, while the ML is all the husbands, this is a multi couple drama where each sister have their own love story and take the lead one by one^^
*Each lineage has a different role and responsibility in Gong family.