Akihi has always resented Haruhi, her twin sister, for being the focus of their parents' praise and attention. This jealousy extends to the point of Akihi seducing Haruhi's husband and having a child with him just to "have something that Haruhi can't have", taking advantage of Haruhi's infertility and in spite of not wanting children herself. However, despite feeling that she has "won", Akihi is still deeply insecure when it comes to her sister.