Aki lives a charmed life. Popular, beautiful, athletic, and at the top of her class, she rules the school, and at home, her younger brother Sora caters to her every whim. Her younger sister Nami, however doesn't have it so easy. The small-chested and sarcastic girl is in love with her best friend - who has a crush on Nami's twin brother Sora - but her life could be worse: she could be her brother. Slight, feminine, and bullied by his twin, Sora cooks and cleans for the entire family. In addition, he harbors a deep-seated lust for his older sister, Aki. Will Sora get over his fantasies or give in to his desires? Will Nami ever win the heart of her best friend? And what does Aki want out of all of this?
What do you do when you live together with gorgeous twin sisters who are intent on seducing you? This is the daily dilemma that faces Keita Suminoe, and politely declining their offers doesn’t seem to be helping him! Despite his school friends' jealous quips, and parents who think everything is fine as the siblings are not blood-related, this makes no difference to the brow-beaten boy. Unfortunately for Keita, school entrance exams are just around the corner, and scantily-clad girls sneaking into his bedroom at night is starting to affect his chances of graduation. Can he focus his mind in time, or will breasts, panties and milky-white thighs prove to be too much of a distraction?
If relationships between a brother and a sister are what you are looking for Koi Kaze and Aki Sora are the series for you. The character development in either one is not lacking. These two series also demonstrate the gravity of a relationship in this type of world.