Mizuki my elder sister... Even though she's all grown up, still so innocent and pure. At least, her mind is. Her body on the other hand... BAM! She attracts guys like moth to a flame. So I've got to protect her. That's what brothers do y'know. One day though, she got duped by the wrong crowd and now... I don't know what she's doing, but I'm worried... (Story about an unwitting immature 'blonde' unwittingly turned slut.)