Kou has gone to an all boys private school because he's in love with his naive and sweet stepbrother Naruki. But when Naruki follows him to the school Kou's life gets very hectic, defending his innocent brother from other students. Kou's roommate Yoshino comes up with a plan for Naruki to fend for himself, but his motives aren't entirely innocent. Additional story : Only You Are Pure Model Satoru loves his best friend Riku. But Riku only mothers him.