SSIS-300 Alone with my girlfriend's beautiful older sister... A sudden tongue kiss, a naughty licking, and a immersion in sex. Am I the worst like this...? - Tsukasa Aoi

Suddenly, his girlfriend's older sister comes to the apartment he lives with. - "Can I stay over tonight?" The two of them are confused by the older sister who has returned home but doesn't go back to her parents' house. - The next day, she goes to Tokyo to look for a job and replace her sister. - "It's okay, just keep it a secret from my sister..." For three days without my girlfriend, I was alone with my beautiful sister. - I was turned on by my older sister Tsukasa's deep kisses and naughty licking sex... - The best masterpiece of reverse NTR drama is born here!