even aoi chan will not have a chance to know that she is her step sister, Rika would be very happy to see her invited on her wedding, maybe even with her dad (even though her mom would be very subjective to it)
one good thing to point out here is that her mom's reason about objecting the wedding is not about marriage or even about her past failed marriage, it's all about being selfish not to lose Rika, even though its like that, it's expected it's much harder to be apart from your offspring if you're a single parent.
anyways it's getting near to the end soon guys. as July is very near for its final volume release, its been a great journey reading with you!