完璧なはずの姉貴・六花が、まさかの‘テク不足’で振られて帰ってきた！プライドをズタズタにされた彼女が八つ当たり気味に目をつけたのは、格下扱いの「コミュ障ボッチな弟」のチ○ポ！そこからは理性をかなぐり捨てた24時間の執念特訓がスタート。朝っぱらから「チ○ポ貸して！」と股間に食らいつき、掃除フェラから玉舐めまで、下品な音を立ててしゃぶり倒す！寝ている弟を夜●いして勝手に逆睡眠姦！練習のはずがいつの間にか弟のチ○ポ中毒になって、メスの顔で誘惑してくる豹変ぶり…！？最後は抜かずの連撃中出し！背徳の追撃痴女トレーニング！
Rikka, the older sister who was supposed to be perfect, has been dumped for a surprising lack of skill and has returned home! Her pride shattered, she takes out her frustration on her socially awkward, lonely younger brother's dick! From there, she throws all reason aside and begins a 24-hour obsessive training session. First thing in the morning, she latches onto his crotch, demanding to borrow his dick, and sucks it mercilessly, from cleaning blowjobs to ball licking, making vulgar noises! She even s her sleeping brother at night and performs a reverse sleep **** on him! What started as practice quickly turns into her becoming addicted to her brother's dick, and she transforms into a seductive woman who tempts him…!? Finally, she finishes with a barrage of cumshots without pulling out! A depraved, relentless training session for slutty women!

– JavGG.net