"I want to be fucked like my sister!" Aina finds out that her sister Reina has become her stepbrother Shota's sex toy. Unable to resist Reina having all of Shota to herself, Aina finally makes a move on Shota...!? She tries to take the lead using the techniques she learned from spying on Shota's actions with Reina, but the genuine pleasure makes Aina aroused without stopping! Aina is also being fucked along with her sister Reina...!