So, this is a oneshot I remember reading here, but I think it got removed. It was set in a world where aliens called the Arume were attacking, but it wasn’t part of the Blue Drop franchise. Women in this world had another, weaponized alien implanted into their hands in order to fight (men seemed to be incompatible with it). The main character was a high school girl, and the guy she had a crush on either had a girlfriend or she thought he did. She masturbates thinking of him shortly after getting the implant, and the alien ends up embedding in her genitals. An alien threat shows up at school, and she ends up saving her crush’s girlfriend, but outing the fact that the alien got embedded in her, well, you know…