Ruru-chan, a young girl in a box who has developed a complex, has discovered the joys of sex and love through sex with her friend and has been trained to be a dirty girl by him. With her fragile expression and slender body, Ruru looks much doesn't look her actual age, but now she is crazy about her friend's cock. Today, she licks and sucks it as the old man taught her, making it bigger and bigger, and then straddles his waist and welcomes it into her precious parts, moving it up and down to make him feel better.