A high school girl who is very interested in love and sex watches AV with her childhood friend! She can't contain her excitement at her first adult video! The two have been good friends since they were little and didn't think of each other as the opposite sex. Although they understand that it is wrong to do so, they are overcome by their innocent Kokoro and straightforward sexual desires, and say, "Let's study sex in secret from our mothers...we'll just be friends from tomorrow!" The whole story of their sex is completely secretly filmed.