Ane wa Oyaji ni Idakareteru Synopsis of Additional Chapters

The first story that occurs after chapter 3, (page 305) occurs before the younger brother discovers Naoto and yuika having sex.

On that occasion, Naoto went outside the apartment and calls Yuna, but she prefers to have sex before answering him..... During this episode, Naoto questions why he feels empty, while his sister is happy, and in fact that no longer has a place in that family when Yuna is already pregnant with her second child

After Yuna and her father finish having sex, Yuna answers and tells him that she didn't answer because she was having sex and Naoto and that she is glad to know, but this time Naoto doesn't answer, which implies that He finally decided to get away from Yuna and her father.

In this way we can understand the attitude of the younger brother and why he calls him "Oyaji" (Old Man), since he does not know who Naoto is and for that reason he does not understand why he and his sister are naked.

Another thing that we were able to discover from the second story (which seems to happen after chapter 3) is that apparently, Naoto seduced his sister and after they started having a relationship, he revealed that they were both brother and sister, since in that story she says that she was very surprised to find out that they both had the same blood.

In this chapter, Yuika tells how dissatisfied she is for various reasons, such as the fact that being siblings they cannot marry or have children, or the fact that she has realized that everything she does such as asking her to wear costumes or recording her, as well as lying to her saying that he loves her, which makes her think that Naoto is obsessed with someone... she suspects that it is his mother, and feels sorry for him since he never had any chance with his father, since his mother was deeply in love with him.

However, despite all this, Yuika has decided to support her uncle to get out of his depression and realize that he is a great man.

The last story concludes with Yuika complaining that she knows that when he lies to her, he looks her in the eyes and that if he continues like this she will leave him..... after which she tells him that she will continue by his side supporting him in everything, or is it that you are in love with your sister?