Attacking the Girls' Dormitory of Demon King

The modern-day lady-assassin found herself transmigrated into a trashy European-fantasy otome game, where she has to make the Demon Lord fall in love with her in order to save the world. Instead, she trained the villainess Lady Lisa in assassin's skills, hoping that Lisa would eventually kill her and allow her to return to the real world. But all that intimate physical contact and her own earnestness during the training caused Lisa to fall in love with her instead?