Substitute flesh servant – 10 days of confinement with a man who never stops ejaculating

身代わり肉便器 射精しても射精しても終わらない絶倫極道オヤジとの10日間監禁生活 相沢みなみ

Minami’s brother has been hanging out with shady people, and he acquired debts that he cannot repay. Minami herself gets approached by Nakata the Yakuza and told that she could repay the debt in full, with her own body. Nakata and Minami together once again, a fantastic actor combo.