I would love to make a game using Koikatsu, but the cost of the software is too prohibitive for me given I have no clue how to even use to make a game in the first place. If I could get a hold of an english language version of the Koikatsu party application with all models, assets and so on, I would love to give it a try.
I have never made a game either in renpy or anywhere else, but I have great ideas for stories. I would also make an renpy game, but i can't program, and by the time I could, and by the time I learned how to render etc etc it would be years down the road, without a team or someone helping me.
Did Corrupted Kingdom no get added on this site? That too was made using Koikatsu, but i don't know if they used the app or they did it another way.