Writer of that fic here! I do plan on making a sequel to that story, but I'm currently busy with writing the second chapter for the story I did on the /m/ag. I'm also working on a ero-fic of KikixMichel from 08th MS team. Once I'm done with those I'll start working on the sequel. I'd already thought up a good premise for it.>It's been one since you and your girlfriend, Puru Two, "express" their feelings for each other. Since then you and Puru Two have "explored" each others' bodies more often. As the days are getting hotter, you and Puru Two decide to take a trip to the beach together. However, once you meet up with Puru Two, you see that she's bring along her clone sister, Marida, with you. You are certain of the sisters' intentions, you just hope you'll be able to have enough energy and "juice" to spare.
I also thought of two other possible sequels to do. One is MC-kunxPuru TwoxLeina, and the other is Puru Two suddenly wakes up with an older body, and wants to try it out on MC-kun.