To discuss the lore and world building for a bit, someone on Reddit brought up that Hinata and Sakura may be half-sisters.
To quote what they said:
"Ok, with this chapter, I have strong suspicions to believe that the author is setting Hinata up to be Sakura's half sister by father.
Here are the hints.
- In chapter 201, Misaki alludes to the phenomenon of "father sharing" by sperm donor, when talking about the picture with Sakura.
- In this scene we see Hinata doing a fabric crease grab with trembling. In the Misaki visit arc, Sakura does the same in chapter 138 with the couch.
- The last image of chapter 132, Sakura cannot shake the feeling that they have met somewhere before. This plot thread has yet to be resolved.
They also share some personality tendencies, being the most outwardly composed of their respective group of 3, but also having a strong predisposition towards the yandere personality.
With all the hinata lore dropping so far about her relationship to her mother (which is alluded to be not great, given her enviousness towards Akane as well as alluded to during her monologue in chapter 158) it might be setting something up for a greater Hinata arc in the near future"
I agree with the comment that they dropped and I assume that we will see more half-siblings within the cast in the future due to how the state of the world is with men and their sperm being shared for procreation purposes due to gender imbalance. With the shared sperm donor knowledge we can also assume that Sumire may also be related to Hana and Aya. They have the same quirks and personalities as well.
So if our theories are right then, Hinata and Sakura are half-sisters; and Aya, Hana and Sumire are half-sisters as well.