Shota, a Rei Kurumugi, a big-assed older sister who is kind and caring towards her younger brother! When Rei finds out that her brother is being bullied, she scolds him. However, Shota makes a lewd trade-off in exchange for her stopping the bullying! Rei offers her butt to Shota for the sake of her brother... He gets excited by the denim butt, faints at the thong butt, and goes crazy at the bare butt! Shota's killer butt-torture play explodes against the firm butt that is over 90cm!