Kana, the older sister, brought her boyfriend home. Seeing the two of them enjoying creampie sex in the room, the selfish younger sister Yui plots to steal her older sister's boyfriend, seducing him with her charms, sucking his balls, licking his asshole, and making him fall in love with Yui's body with her amazing sex techniques. Kana, whose boyfriend was stolen from her, presses him, asking "Which one feels better?" and they decide to check their physical compatibility with a threesome... The two girls sandwich the boyfriend between their breasts, compete for him with a double blowjob, ride him with their legs spread, and fuck him with their pussies stacked together in the ultimate pleasure of a sister threesome!