Phantom Alchemia: Sylvia no Dokidoki Sakusei Toshi Keikaku

Based on the erotic doujin game by Trynity.Lab.
In order to make up for the corruption committed by her father, Silvia had to help the development of the border city as an alchemist. But if she wants to use alchemy, she must convert the spiritual power of residents into energy. To shoulder the mission, Silvia collected spiritual power while using Alchemy to enrich people's lives. However, after gaining the recognition of the residents, Silvia accidentally discovered the [truth] of alchemy.
(Source: Steam)