Okay, I have another little explanation why Sasha may very well be related by blood to Nami and Nika.
The answer,oddly enough, lies in this site.Incest patch.Ocean,although allows such relationships in the plot, but tries to weave it into the plot, make it more realistic and of course show the consequences.Such relationships will always be secretive, and most people will not accept it.Sadly, the *official* version prohibits incest.However,by removing the patch,the viewer may have a lot of questions about why,according to the plot, they are so hidden.Here lies the trick and the author’s solution to the problem. Absolutely all girls who are blood related to MC and are love interests will ALWAYS have a very difficult personality, uncommon difficult past with MC and/or a plot in which the relationship will have to be hidden.
Judge for yourself: Nami has a difficult, unclear past with MC, very jealous and envious.Leia has a difficult past with MC,a dark, cold, jealous mafioso. Katie has a difficult past with MC, a rare bitch, she is just as manipulative as Leia and also has feelings for William in her own twisted masochistic manner. I am sure that with Helen there will be many more turning points, although there were already hints that she is completely another and Leia may still seem like an angel in comparison.
Now take Sasha. A difficult character, the habits of a stalker with hints of a yandere,a princess from a very rich, powerful crime clan. Yes, there is a whole set of red flags that this will be an incredibly difficult path in which they will hide their relationships.It seems to me that the chances that Nami and Sasha are twins, and Nika their younger brother, are quite high. What do you think?