*Author's note: I am aware of the rules regarding copyrighted characters so any video game character's mentioned in this story are fake. Though they are inspired by certain actual characters, none of those characters are directly mentioned. Hope this abides by that rule.*
Jeff had a particular hunch at what he could do with the Chronivac and wanted to just test out the full extent of it's capabilities. Pulling up his Big sisters profile into the Chronivac, he watched as all the information about her was listed on the screen. Her physical traits and sizes, as well as her thoughts and feeling regarding different subject matters. It even listed the thoughts she had regarding everyone she was close to, including what she thought of Jeff.
"Perverted, a bit stupid but overall kind. So that's what Steph thinks of me, huh? Could be worse I suppose." Jeff mumbled to himself as he thought of what to do. Looking more at Stephanie's profile, it displayed her hair colour being blonde and eye colour being green, as well as the fact that she was the cheerleader captain at her high school. All of this was helpful with the plan Jeff had for her.
Sure he could just test somethings on himself, but what he wanted to try out needed to be done on someone else if he wanted to see the full effects, and he just so happened to pick his sister for it.
Pondering a little, Jeff opened up VNDB (Visual Novel Data Base) to look up a specific visual novel that he had pirated and played for his own amusement. The visual novel was something like 'Boobilicious babes' or something along those lines, and all the female characters in the visual novel had breasts larger than their heads. Jeff's plan involved one of these characters and he sister, and he wanted to see if he could swap his sister with said character.
Scrolling through the character list on VNDB for the visual novel, he found a character named Sayaka Sayuri (not a real character). Physically, she was portrayed as having P cup breasts and long flowing pink hair that reached her waist. She was also apparently a college volleyball player which was the source of various lewd endeavours between the male protagonist and her. Other traits of hers was easily flustered and aroused, and highly sensitive to being kissed, having cummed from being kissed in the visual novel. Thinking about it, Jeff went with her.
Programming the changes into the Chronivac, Jeff's plan was to make his sister become part of the visual novel as one of the characters, whilst Sayaka would become his sister. At least temporarily. Setting up the swap, Jeff hit enter and was immediately greeted by a second window displaying a message. On said message seemed to be a waring of some kind.
"Resulting swap will require physical alterations to individuals' traits to proceed. Do you wish to allow these changes to take place?" Jeff read out in a monotonous tone as he thought about it. "Sure, why not? What's the worst that could happen?" Proceeding with the changes, Jeff hit enter and waited for whatever change was about to happen.
Except, nothing seemed to have happened. The Chronivac loaded the input instantly and nothing regarding his surrounding changed although that was expected given the targets. "I know my sister and that hentai character named Stephanie were the targets but I would have thought there would be a little more fan fare to the change." As soon finished that sentence, it dawned on him at what he actually had said. Stephanie, who he remembered being his sister, immediately registered as a Hentai character, and Sayaka as his sister. "I need to go down and check something."
Leaving the Chronivac for a little while, Jeff went across the hall and headed towards where his sister's room was. Peaking inside, most of the room was how he remembered it, except now there were some volleyball posters on the wall and someone who he registered as his sister, but also not at the same time. On his sister's bed was a girl with huge breasts and long pink hair, dressed in a casual pair of shorts and a shirt that exposed a lot of cleavage. Just from looking at her, she physically had the same traits as Sayaka from the visual novel, but instead of a cartoony art style, she was real.
"Hmmm? What's the matter little brother?" Sayaka looked over from her phone and looked at Jeff, who was a little flustered at being noticed.
"Oh, uhhh~ nothing. Just checking up on you." Jeff said the first thing that came to his mind for an excuse.
"Awww, what a sweet little brother you are." Sayaka cheerfully exclaimed which caused Jeff to get even more flustered. If Stephanie was the one sat on her bed, she'd just tell Jeff to go away, but Sayaka was far more receptive of him.
Making a mental note of that, Jeff waved bye to Sayaka and headed back to the Chronivac, while pulling something up on his phone. "If Sayaka is there, does that mean that Stephanie is-?" Thinking about what might have happened, as soon as Jeff opened up VNDB on the visual novel again, what he saw amazed him. Where Sayaka used to be on the promotional stuff for the visual novel, an anime stylised version of Stephanie was there, and that wasn't all. While Jeff knew that Stephanie was at most a C or D cup, this Stephanie was certainly far larger, and she also was dressed in the lewd outfits, typical for the girls of the visual novel.
Opening up her character traits on VNDB, it displayed her size as being U cup and being into making cheer routines for the main characters dick. "I guess she is still a cheerleader as a hentai character. Funny. I guess that pop up window was meant to signify changes that Steph would face when getting turned into an Eroge character."
Still a little curious at the extent of the changes, Jeff looked up the CGs of the game online, as well as fanart of the characters. His results and what he found were further surprises, as the CGs of Stephanie had difference angles and compositions then the ones that existed for Sayaka, and the fanart of Sayaka all now displayed Stephanie instead, with some slight changes if necessary. "How very interesting. Makes me wonder what would happen if I were to turn other people I know into eroge characters."
With that thought, Jeff considered what to do next.