Found these two totally by accident, they were made by the same author.
Maybe they're not that interesting since there's no certain plot for both games, but hey, at least there are people who tried to make some spin-offs, eh?
First is a tiny adventure game starring Mirai Kasuga, which does not contain a full plot.
Get MiLLiON B@TTLE!ぷち
HEREYou can set the main character to whoever you want after clearing all four stages for once.
Second is kind of a farming game features Hinata Kinoshita, earn money with your crops to exchange dress-up doodles, and go to the deepest layer of the mining pit for your secret reward.
Get ひなたと牧場
HEREScreenshots for both game:
