This is definitely a situation that will tempt you. When you go to your girlfriend's house to hang out, you suddenly meet her sister's eyes. At first, you probably didn't notice each other, but as it happens again and again, you gradually feel like you're doing something naughty... What if your girlfriend happens to be away and only her sister is there at that time? An office lady... a female college student, a prep school student, a cram school teacher... you're seduced by her sister at her house... the desire to try something a little more mature than your girlfriend grows during the lewd time while she's away. A delicate and naughty relationship, all filmed for the first time in 6 chapters.