We were all stepchildren and close in age, so we quickly became close. But the relationship between the three of us changed dramatically during the three days our parents were away. During spring break, a time of change in seasons and environments, I was so bored that I was just lazing around at home when my brother said, "Big brother, you look at Ichika with dirty eyes Ichika, don't you?" I was feeling embarrassed, and then suddenly he kissed me... I lost all sense of reason. Even when Kanna came home, my sexual desire didn't stop. Influenced by us, even the serious Kanna started to want to have sex with us... We just fucked like crazy.