Oniichan wa Oshimai! Episode 12 English Subbed Episode Title: Mahiro's Future as a Sister Episode Description: As planned, they stay at an onsen together with Asahi and Miyo for one night. In the middle of playing with his friends at the pool, Mahiro's drug slowly wears off and his penis grows back. Without anyone noticing it, he storms back to the hotel room with Mihari who presents him with a backup potion, telling him to consider that it will make him stay female for "a long time" if taken. After taking the evening's time to reflect on it, he decides to drink it. On the way home by train, Mihari reveals to him that her conspiring rehabilitation project has been overly successful.