Phantom Alchemia: Silvia no Dokidoki Sakusei Toshi Keikaku

Sylvia (or Silvia/Sylvia), an ordinary sheltered girl living alone deep in the mountains, is visited by a man named Steve. He takes her to the remote border city of Elanberg (or Elanbelk). Without understanding why, she is suddenly pushed down and roughly raped by him, losing her virginity in a traumatic first experience. Despite the shock and pain, Sylvia soon feels a mysterious power surging through her bodyshe has unknowingly awakened a hidden talent for alchemy, powered by absorbing semen as spiritual/energy source. Entrusted with developing and revitalizing the struggling town using her new powers (to atone for her fathers corruption or fulfill a contract replacing her missing mother), the novice big-breasted alchemist must now collect vital essence (semen) from men in the city. This fuels miraculous spells that improve infrastructure, agriculture, and daily life for the residents. She realizes with dread (and growing reluctant pleasure) just how many men shell have to take inside her to accomplish her mission, marking the start of her erotic town-building journey filled with sex in various settings.