Naughty Instinct.

Episode 1: Atsushi and his sister Naomi live under the same roof. Despite her strong love to her brother, Naomi buries her real emotion deep in her heart, and she can only express her feeling in the virtual computer domain. Meanwhile, Naomi’s college friend pursues her strongly, but she still cannot forget her brother. To heal her broken heart, Naomi decides to run away to America… Episode 2: Kumiko is currently living with her brother Tatsuya who is back from overseas. Kumiko has always hidden her feeling from her brother, but she can hold it back against her passion no more when the two grown-ups live together once again. One day, Tatsuya discovers his sister’s secret accidentally from her blog and therefore decides to disclose his secrets to Kumiko too. Since then the situation is only getting uncontrollable…